Calculate the  t test stat for  testing the claim the average waiting time is more than 20 minutes  also find the pvalue for testing the claim by entering  probability t distribution df=99>test stat  into wolframalpha.com for example if your test is 1,2 enter  probability t distribution df=99>1.2  into wolframalpha.com Note that in question you use wolframalpha.com ,  You might not have access to wolframalpha,com  in the exam but you do have access to the  t table, using the t table   t,0.05,99  =1.66 so you know the Pvalue will be less than 0.05 if the test stat is more than 1.66  a. the Pvalue is 0.01 b. the Pvalue is -0.09 c. the test stat is 2.44 d. the test stat is 2.54

suppose in a sample of 100 customer the average   waiting time is   22.54 minutes 
with a standard deviation of 10 minutes 

Calculate the  t test stat for  testing the claim the average waiting time is more than 20 minutes 
also find the pvalue for testing the claim by entering 
probability t distribution df=99>test stat 

into wolframalpha.com
for example if your test is 1,2
enter 
probability t distribution df=99>1.2  into wolframalpha.com

Note that in question you use wolframalpha.com ,  You might not have access to wolframalpha,com  in the exam but you do have access to the  t table,
using the t table   t,0.05,99  =1.66

so you know the Pvalue will be less than 0.05 if the test stat is more than 1.66