Question

I want to know if performance enhancing drugs have an effect on batters in the MLB. I think that PEDs would allow batters to swing their bat faster, so I measure the time it takes for 100 batters to complete their swing. The mean response time for the batters without PEDs is 1.2 seconds to complete their swing. After I inject the batters with steroids, the mean of their response times is 1.05 seconds to complete their swing, with a sample standard deviation of 0.5 seconds.

Calculate the p-value. Given this p-value, I…Reject my null hypothesis or Fail to reject my null hypothesis

Answer 1

Solution :

= 1.2

=1.05

S =0.5

n = 100

This is the two tailed test .

The null and alternative hypothesis is ,

H0 :    = 1.2

Ha :     1.2

Test statistic = t

= ( - ) / S / n

= (1.05-1.2) / 0.5 / 100

= -3.0

Test statistic = t = -3.0

P-value =0.0034