Data

1. What is the demographic profile of the respondents in terms of:


Attaching package: 'dplyr'
The following objects are masked from 'package:stats':

    filter, lag
The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

Sex

Strand

Daily Screen Time

The tables above provides the distributions of respondents in terms of sex, strand and daily screen time. It can be seen that there are 72 females and 28 males; 20 of which are from ABM, 20 from GAS, 40 from HUMSS, and 20 from STEM. Moreover, 26 students have a daily screen time of 1-2 hours, 24 for 3-4 hours, 22 for 5-6 hours, and 28 for more than 6 hours.

2. Is there a significant difference on the variables academic proficiency, physical and mental health, and social interactions when grouped according to:

2.1 Sex


Call:
lm(formula = `Academic Proficiency` ~ `Mental Health` + `Physical Health` + 
    `Social Interactions`, data = Data)

Coefficients:
          (Intercept)        `Mental Health`      `Physical Health`  
              1.31602                0.24408                0.18613  
`Social Interactions`  
              0.05491  

From this, we may deduce that the data fail to satisfy two assumptions – Linearity and Homogeneity of Variance.

Loading required package: carData

Attaching package: 'car'
The following object is masked from 'package:dplyr':

    recode
── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
✔ forcats   1.0.0     ✔ readr     2.1.5
✔ ggplot2   3.4.4     ✔ stringr   1.5.1
✔ lubridate 1.9.3     ✔ tibble    3.2.1
✔ purrr     1.0.2     ✔ tidyr     1.3.1
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
✖ car::recode()   masks dplyr::recode()
✖ purrr::some()   masks car::some()
ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors

Attaching package: 'rstatix'


The following object is masked from 'package:stats':

    filter

2.1.1 Sex and Physical Health

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Physical Health`
W = 0.92897, p-value = 4.352e-05

Since p-value = 4.352e-05 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  1  0.5427 0.4631
      98               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.


Attaching package: 'gplots'
The following object is masked from 'package:stats':

    lowess
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 2 × 11
  Sex    variable            n   min   max median   iqr  mean    sd    se    ci
  <fct>  <fct>           <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Female Physical Health    72   1.6   3.4    2.8   0.4  2.73 0.329 0.039 0.077
2 Male   Physical Health    28   1.6   3.4    2.7   0.4  2.69 0.387 0.073 0.15 

The mean of female and male is 2.731 and 2.686, respectively.

Mann Whitney U Test

# A tibble: 1 × 6
  .y.                 n statistic    df     p method        
* <chr>           <int>     <dbl> <int> <dbl> <chr>         
1 Physical Health   100     0.471     1 0.492 Kruskal-Wallis

Based on the p-value, there is no significant difference on the physical health when grouped according to sex.

2.1.2 Sex and Mental Health

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Mental Health`
W = 0.9454, p-value = 0.000418

Since p-value = 0.000418 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  1  0.1865 0.6668
      98               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 2 × 11
  Sex    variable          n   min   max median   iqr  mean    sd    se    ci
  <fct>  <fct>         <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Female Mental Health    72     2   3.2    2.6  0.4   2.65 0.297 0.035 0.07 
2 Male   Mental Health    28     2   3.2    2.6  0.45  2.61 0.333 0.063 0.129

The mean of female and male is 2.647 and 2.607, respectively.

Mann Whitney U Test

# A tibble: 1 × 6
  .y.               n statistic    df     p method        
* <chr>         <int>     <dbl> <int> <dbl> <chr>         
1 Mental Health   100     0.212     1 0.645 Kruskal-Wallis

Based on the p-value, there is no significant difference on the mental health when grouped according to sex.

2.1.3 Sex and Academic Proficiency

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Academic Proficiency`
W = 0.94945, p-value = 0.0007636

Since p-value = 0.0007636 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  1  0.0236 0.8783
      98               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 2 × 11
  Sex    variable             n   min   max median   iqr  mean    sd    se    ci
  <fct>  <fct>            <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Female Academic Profic…    72   1.6   3.2    2.6  0.4   2.60 0.305 0.036 0.072
2 Male   Academic Profic…    28   1.8   3.2    2.6  0.45  2.63 0.325 0.061 0.126

The mean of female and male is 2.597 and 2.629, respectively.

Mann Whitney U Test

# A tibble: 1 × 6
  .y.                      n statistic    df     p method        
* <chr>                <int>     <dbl> <int> <dbl> <chr>         
1 Academic Proficiency   100     0.225     1 0.635 Kruskal-Wallis

Based on the p-value, there is no significant difference on the physical health when grouped according to sex.

2.1.4 Sex and Social Interactions

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Social Interactions`
W = 0.9488, p-value = 0.0006918

Since p-value = 0.0006918 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value  Pr(>F)  
group  1    5.35 0.02281 *
      98                  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

The p-value is less than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is not met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 2 × 11
  Sex    variable             n   min   max median   iqr  mean    sd    se    ci
  <fct>  <fct>            <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Female Social Interact…    72   2     3.2    2.6   0.4  2.57 0.323 0.038 0.076
2 Male   Social Interact…    28   1.2   3.8    2.6   0.6  2.54 0.547 0.103 0.212

The mean of female and male is 2.572 and 2.536, respectively.

Mann Whitney U Test

# A tibble: 1 × 6
  .y.                     n statistic    df     p method        
* <chr>               <int>     <dbl> <int> <dbl> <chr>         
1 Social Interactions   100     0.280     1 0.596 Kruskal-Wallis

Based on the p-value, there is no significant difference on the physical health when grouped according to sex.

2.2 Daily Screen Time

2.2.1 Daily Screen Time and Physical Health

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Physical Health`
W = 0.92897, p-value = 4.352e-05

Since p-value = 4.352e-05 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  3  1.4341 0.2376
      96               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 4 × 11
  `Daily Screen Time` variable      n   min   max median   iqr  mean    sd    se
  <fct>               <fct>     <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl>
1 1-2 hours           Physical…    26   1.6   3.4    2.8  0.6   2.71 0.413 0.081
2 3-4 hours           Physical…    24   2     3      2.8  0.4   2.78 0.272 0.056
3 5-6 hours           Physical…    22   2     3.4    2.8  0.55  2.73 0.363 0.077
4 More                Physical…    28   1.6   3.4    2.6  0.2   2.67 0.328 0.062
# ℹ 1 more variable: ci <dbl>

The mean of 1-2 hours, 3-4 hours, 5-6 hours, and more is 2.708, 2.775, 2.727, and 2.671, respectively.

Kruskal-wallis Test

# A tibble: 1 × 6
  .y.                 n statistic    df     p method        
* <chr>           <int>     <dbl> <int> <dbl> <chr>         
1 Physical Health   100      2.00     3 0.571 Kruskal-Wallis

Based on the p-value, there is no significant difference was observed between the group pairs.

2.2.2 Daily Screen Time and Mental Health

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Mental Health`
W = 0.9454, p-value = 0.000418

Since p-value = 0.000418 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  3  0.7506 0.5246
      96               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 4 × 11
  `Daily Screen Time` variable      n   min   max median   iqr  mean    sd    se
  <fct>               <fct>     <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl>
1 1-2 hours           Mental H…    26   2     3.2    2.6  0.4   2.65 0.318 0.062
2 3-4 hours           Mental H…    24   2.2   3      2.8  0.4   2.68 0.256 0.052
3 5-6 hours           Mental H…    22   2     3.2    2.6  0.55  2.64 0.324 0.069
4 More                Mental H…    28   2     3.2    2.6  0.45  2.59 0.331 0.063
# ℹ 1 more variable: ci <dbl>

The mean of 1-2 hours, 3-4 hours, 5-6 hours, and more is 2.654, 2.675, 2.636, and 2.586, respectively.

Kruskal-wallis Test

# A tibble: 1 × 6
  .y.               n statistic    df     p method        
* <chr>         <int>     <dbl> <int> <dbl> <chr>         
1 Mental Health   100      1.15     3 0.765 Kruskal-Wallis

Based on the p-value, there is no significant difference was observed between the group pairs.

2.2.3 Daily Screen Time and Academic Proficiency

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Academic Proficiency`
W = 0.94945, p-value = 0.0007636

Since p-value = 0.0007636 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  3  0.5001 0.6831
      96               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 4 × 11
  `Daily Screen Time` variable      n   min   max median   iqr  mean    sd    se
  <fct>               <fct>     <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl>
1 1-2 hours           Academic…    26   2     3.2    2.6  0.35  2.67 0.315 0.062
2 3-4 hours           Academic…    24   2     3.2    2.5  0.4   2.53 0.281 0.057
3 5-6 hours           Academic…    22   2.2   3      2.8  0.2   2.7  0.26  0.055
4 More                Academic…    28   1.6   3.2    2.6  0.4   2.54 0.344 0.065
# ℹ 1 more variable: ci <dbl>

The mean of 1-2 hours, 3-4 hours, 5-6 hours, and more is 2.669, 2.533, 2.700, and 2.536, respectively.

Kruskal-wallis Test

# A tibble: 1 × 6
  .y.                      n statistic    df      p method        
* <chr>                <int>     <dbl> <int>  <dbl> <chr>         
1 Academic Proficiency   100      6.75     3 0.0804 Kruskal-Wallis

Based on the p-value, there is no significant difference was observed between the group pairs.

2.2.4 Daily Screen Time and Social Interactions

Normality Test


    Shapiro-Wilk normality test

data:  Data$`Social Interactions`
W = 0.9488, p-value = 0.0006918

Since p-value = 0.0006918 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
      Df F value Pr(>F)
group  3  1.7959 0.1531
      96               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 4 × 11
  `Daily Screen Time` variable      n   min   max median   iqr  mean    sd    se
  <fct>               <fct>     <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl>
1 1-2 hours           Social I…    26   2     3      2.6  0.6   2.53 0.325 0.064
2 3-4 hours           Social I…    24   2.2   3      2.6  0.4   2.57 0.255 0.052
3 5-6 hours           Social I…    22   2     3.8    2.4  0.75  2.56 0.46  0.098
4 More                Social I…    28   1.2   3.8    2.6  0.4   2.59 0.505 0.095
# ℹ 1 more variable: ci <dbl>

The mean of 1-2 hours, 3-4 hours, 5-6 hours, and more is 2.531, 2.567, 2.564, and 2.586, respectively.

Kruskal-wallis Test

# A tibble: 1 × 6
  .y.                     n statistic    df     p method        
* <chr>               <int>     <dbl> <int> <dbl> <chr>         
1 Social Interactions   100     0.766     3 0.858 Kruskal-Wallis

Based on the p-value, there is no significant difference was observed between the group pairs.

Is there a significant difference between academic proficiency, physical health, mental health, and social interactions?

Normality Test


    Shapiro-Wilk normality test

data:  Data1$Scores
W = 0.95675, p-value = 1.956e-09

Since p-value = 1.956e-09 < 0.05, it is conclusive that we reject the null hypothesis. That is, we cannot assume normality.

Equality of Variance

Warning in leveneTest.default(y = y, group = group, ...): group coerced to
factor.
Levene's Test for Homogeneity of Variance (center = median)
       Df F value Pr(>F)
group   3  1.2869 0.2785
      395               

The p-value is greater than the 0.05 level of significance. Thus, the homogeneity assumption of the variance is met.

Warning: Removed 1 rows containing non-finite values (`stat_boxplot()`).

Warning: Removed 1 rows containing non-finite values (`stat_summary()`).
Warning: Removed 1 rows containing missing values (`geom_point()`).

Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter
Warning in axis(1, at = 1:length(means), labels = legends, ...): "frame" is not
a graphical parameter
Warning in plot.xy(xy.coords(x, y), type = type, ...): "frame" is not a
graphical parameter

# A tibble: 4 × 11
  Variables      variable     n   min   max median   iqr  mean    sd    se    ci
  <fct>          <fct>    <dbl> <dbl> <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Academic Prof… Scores     100   1.6   3.2    2.6   0.4  2.61 0.309 0.031 0.061
2 Physical Heal… Scores     100   1.6   3.4    2.8   0.4  2.72 0.345 0.034 0.068
3 Mental Health  Scores     100   2     3.2    2.6   0.4  2.64 0.307 0.031 0.061
4 Social Intera… Scores      99   1.2   3.8    2.6   0.4  2.56 0.395 0.04  0.079

The mean of Academic Proficiency, Physical Health, Mental Health, and Social Interactions is 2.606, 2.718, 2.636, and 2.558, respectively.

Warning: Removed 1 rows containing non-finite values (`stat_boxplot()`).

Kruskal-wallis Test

# A tibble: 1 × 6
  .y.        n statistic    df       p method        
* <chr>  <int>     <dbl> <int>   <dbl> <chr>         
1 Scores   400      14.2     3 0.00264 Kruskal-Wallis

Based on the p-value, there is significant difference was observed between the group pairs.

Pairwise Comparisons

# A tibble: 6 × 9
  .y.    group1        group2    n1    n2 statistic       p   p.adj p.adj.signif
* <chr>  <chr>         <chr>  <int> <int>     <dbl>   <dbl>   <dbl> <chr>       
1 Scores Academic Pro… Physi…   100   100     2.59  9.52e-3 0.0571  ns          
2 Scores Academic Pro… Menta…   100   100     0.531 5.96e-1 1       ns          
3 Scores Academic Pro… Socia…   100    99    -1.08  2.81e-1 1       ns          
4 Scores Physical Hea… Menta…   100   100    -2.06  3.92e-2 0.235   ns          
5 Scores Physical Hea… Socia…   100    99    -3.66  2.48e-4 0.00149 **          
6 Scores Mental Health Socia…   100    99    -1.61  1.08e-1 0.648   ns          

There is significant difference between academic proficiency and physical health, physical and mental health, and physical health and social interactions

4. On which variable have the most significant impact?

Based on the provided output above, we can say that it is the physical health.