Topic 1: Introduction to Statistics and presenting data


These are the solutions for Computer Lab 2.


Preparation

No solution required.

1 Variables in the survey data set

1.1

No solution required.

1.2

No solution required.

1.3

No solution required.

1.4

The variable types for the variables in the survey data set example are:

  • Sex: Categorical, Nominal
  • Wr.Hnd: Numerical, Continuous
  • NW.Hnd: Numerical, Continuous
  • W.Hnd: Categorical, Nominal
  • Fold: Categorical, Nominal
  • Pulse: Numerical, Discrete
  • Clap: Categorical, Nominal
  • Exer: Categorical, Ordinal
  • Smoke: Categorical, Ordinal
  • Height: Numerical, Continuous
  • M.I: Categorical, Nominal
  • Age: Numerical, Continuous

2 Frequency tables

2.1

2.2

Approximately 7.6% of students are left-handed, with the majority (approximately 92.4%) right-handed.

2.3

  • There are 118 females and 118 males students.
  • 50% of the class is female and 50% is male.

3 Types of variables in jamovi

3.1

No solution required.

3.2

4 Adding cumulative frequencies to the table

4.1

While the below table is presented differently from your table, the data contained within it should be the same:

##       Freq Cum Freq Rel Freq Cum Rel Freq
## Never  189      189    80.08        80.08
## Occas   19      208     8.05        88.14
## Regul   17      225     7.20        95.34
## Heavy   11      236     4.66       100.00

5 Bar charts

5.1

5.2

No solution required.

5.3

The difference is in the scale on the \(y\) (vertical) axis: in the relative frequency chart, it represents percentages rather than frequencies.

6 Saving or exporting plots from jamovi

6.1

No solution required.

7 Pie charts

7.1

The “Never” category contains the most number of observations, while the “Heavy” category appears to contain the least, although this is less obvious by looking at the pie chart.

8 Assessing numerical variables

8.1

By referring to the above frequency table, answer the following questions:

  1. How many students are between 170-175cm? \(42\)
  2. What percentage of students are between 170-175cm? \(20.1\%\)
  3. How many students are less than 175cm tall? \(126\)
  4. What percentage of students are less than 175cm tall? \(60.29\%\)
  5. How many students are 175cm or taller? \(209 - 126 = 83\)
  6. What percentage of students are 175cm or taller? \(100 - 60.29 = 39.71\%\)

9 Histograms

9.1

9.2

The data appear to be highly skewed to the right, and we can also see an outlier.


That’s everything for now! If there were any parts you were unsure about, take a look back over the relevant sections of the Topic 1 material.


References


These notes have been prepared by Amanda Shaker. The copyright for the material in these notes resides with the authors named above, with the Department of Mathematics and Statistics and with La Trobe University. Copyright in this work is vested in La Trobe University including all La Trobe University branding and naming. Unless otherwise stated, material within this work is licensed under a Creative Commons Attribution-Non Commercial-Non Derivatives License BY-NC-ND.