In Chapter 16 of the textbook we presented a case study that is associated with an attempt to develop a measure of physical ability. The data of this case study is saved in a file by the name "job.csv". Consider the following R code

> job summary(job) grip arm ratings sims Min. : 29.0 Min. : 19.00 Min. : 21.60 Min. : -4.1700 1st Qu. : 94.0 1st Qu. : 64.50 1st Qu. : 34.80 1st Qu. : -0.9650 Median : 111.0 Median : 81.50 Median: 41.30 Median : 0.1600 Mean : 110.2 Mean 78.75 Mean : 41.01 Mean 0.2018 3rd Qu. : 124.5 3rd Qu. : 94.00 3rd Qu. : 47.70 3rd Qu. : 1.0700 Max. : 189.0 Max. : 132.00 Max. : 57.20 Max. : 5.1700 > t.test(job$arm,mu=75) One Sample t-test data: jobfarm t = 2.1548, df = 146, p-value = 0.03282 alternative hypothesis: true mean is not equal to 75 95 percent confidence interval: 75.31075 82.19265 sample estimates: mean of x 78.7517