Statistical Comparision of Wheat Yield Data with Country-Wide Average Yield

(Splitshire, n.d.)

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Introduction

This is a simulated study that using a range of fake wheat yield data to compare with a country-wide average to showcase the application of One-sample Student’s T-test. Let’s say the countrywide average is 2249 kg/ha, and I have a range of my experimental result:

my.yield <- c(2456, 2365, 2876, 2022, 2498, 2655, 1989, 1994, 2556, 2601)
summary(my.yield)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    1989    2108    2477    2401    2590    2876

Visualisation

Choosing boxplot to quickly visualise these statistical metrics with the country-wide yield average:

Statistical test

Applying one-sided and two-sided method on One-sample Student’s T-tests to find out:

• statistically different, • statistically higher, or • statistically lower.

t.test(my.yield, mu = 2249)

## 
##  One Sample t-test
## 
## data:  my.yield
## t = 1.569, df = 9, p-value = 0.1511
## alternative hypothesis: true mean is not equal to 2249
## 95 percent confidence interval:
##  2181.755 2620.645
## sample estimates:
## mean of x 
##    2401.2

t.test(my.yield, mu = 2249, alternative = "greater")

## 
##  One Sample t-test
## 
## data:  my.yield
## t = 1.569, df = 9, p-value = 0.07555
## alternative hypothesis: true mean is greater than 2249
## 95 percent confidence interval:
##  2223.375      Inf
## sample estimates:
## mean of x 
##    2401.2

t.test(my.yield, mu = 2249, alternative = "less")

## 
##  One Sample t-test
## 
## data:  my.yield
## t = 1.569, df = 9, p-value = 0.9244
## alternative hypothesis: true mean is less than 2249
## 95 percent confidence interval:
##      -Inf 2579.025
## sample estimates:
## mean of x 
##    2401.2

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Conclusion

1. There is no statistical different between experimental mean and the country-Wide mean (P-value>0.05).

2. There is not a strong evidence that the experimental mean is greater than the country-wide mean (P-value>0.05).

3. There is not a strong evidence that the experimental mean is lesser than the country-wide mean (P-value>0.05).

Reference

Splitshire, n.d., Field of growing wheat, https://freerangestock.com/photos/41001/field-of-growing-wheat.html