QUESTION 1 The Cougar Swim Club acquired some Speedo Fastskin bodysuits and deci

ID: 3357020 • Letter: Q

Question

QUESTION 1 The Cougar Swim Club acquired some Speedo Fastskin bodysuits and decided to test them out. A number of the club's fastest swimmers performed a 50m freestyle swim in a regular spandex body Speedo Fastskin suit. The table below summarizes their times in seconds (s) Swimmer spandex 31.1 28.9 31.4 34.9 27.7 36.7 33.3 30.8 Speedo Fastskin 29.1 30.4 25.3 31.7 28.2 32.9 28.6 26.2 Perform a t-test for dependent means to determine if there is a difference between the regular spandex suit and the Fastskin bodysuit in terms of performance Critical value of t- Would you reject the null hypothesis? (use alpha 0.05)

Explanation / Answer

Enter the data into Excel.
Click on Data tab -> Click on Data Analysis toolpack -> t-test : Two sample assuming equal variances -> Click ok.
For variable 1 range : select data for Spandex and for variable 2 range : select data for Speedo -> Hypothesized mean difference = 0 -> Tick the labels -> Click ok.

t-Test: Two-Sample Assuming Equal Variances

Spandex

Speedo

Mean

31.85

29.05

Variance

8.96

6.682857

Observations

Pooled Variance

7.821429

Hypothesized Mean Difference

t Stat

2.002373

P(T<=t) one-tail

0.032503

t Critical one-tail

1.76131

P(T<=t) two-tail

0.065006

t Critical two-tail

2.144787

t-statistic : 2.002373
df : 14
Critical t-value : 2.144787
Since t < critical t-value, we accept the null hypothesis and conclude that there is no significant difference between the performance of the two.