Analysis of Scientific Data - Semester 1, 2022 Week 3 Tutorial Questions Repetitive movements and poor posture are associated with over-use of smartphones and can significantly contribute to symptoms of pain and discomfort in the upper extremities. The severity of these symptoms can be assessed through questionnaires as well as through direct measurements of grip strength (kg). A paper in 2016 presented a study on the effect of an exercise training and postural correction program that aimed to help smartphone users. The researchers recruited 100 university students as potential participants in the study. The students were randomly assigned to either a control group, who received a pamphlet, or an experimental group, who received the new training program. The following quantile plot shows the measured grip strength for all subjects after the study had concluded: Control o Experimental + 45 + xxx 40 XXX x1 35 Grip Strength (kg) 00 xxx 30 xxxx 25 too 0 20 0.0 0.2 0.4 0.6 0.8 1.0 Quantile a) Was this a blind study? Why or why not? b) Estimate the proportion of subjects in the experimental group who had a grip strength of 40 kg or higher at the end of the study. c) Based on the quantile plot, match the following boxplots to their corresponding group (experimental or control): 0 45 - 40 35 Grip Strength (kg) 30 25 - o 0 20
d) Summarise the effects of the experimental treatment on the grip strength outcomes. e) What issues might affect your conclusions in (d)? f) The mean grip strength of the 50 subjects in the experimental group was 35.02 kg. One of those subjects had a grip strength of 24.03 kg. What would happen to the mean if their value was removed from the data? g) The sample variance is the sum of the squared deviations of observations from the sample mean divided by the degrees of freedom. In later modules, we will sometimes want to obtain the sum of the squared deviations from a known sample standard deviation. For example, the standard deviation of the grip strengths of the 50 subjects in the experimental group was 4.559 kg. What was the sum of the squared deviations from the mean? What are the units of this value?