The mean response time of a species of pigs to a stimulus is 0.8 seconds. twenty-eight pigs were given 2 oz of alcohol and then tested. if their sample average response time was 1.0 seconds with a sample standard deviation of 0.3 seconds, can we conclude that alcohol affects the mean response time? use the 5 percent significance level.

Let be the mean response time of a species of pigs to a stimulus.

As per given , we have

Since , the alternative hypothesis is two-tailed and population standard deviation is unknown , so we perform two-tailed t-test.

Also, we have n= 28

Sample mean =

sample standard deviation= s= 0.3

Test statistic :

P-value :  

     [using p-value table for t]

Decision : Since p-value < 0.05 ( significance level ), so we reject the null hypothesis .

Conclusion : We have enough evidence to accept that alcohol affects the mean response time.

∠cbe and ∠deb are same-side interior angles.

i took the test

the answer is 13 cm