Answer:
A)Yes they should market the wax, because it melts before 55 seconds
C) Null hypothesis: mean <55 vs. Alternative hypothesis :mean =55
D) the value is 51.33 seconds
Step-by-step explanation:
The selected samples for the champion are : 57.9, 62.9, 50.6, 50.5,48.2,47.2,50.2 and 43.1
The mean is ;
Sum =57.9 + 62.9 + 50.6 + 50.5+48.2+47.2+50.2+ 43.1 =410.6
Mean= 410.6/8 =51.33= mean
Assuming Significant =0.05 thus applying this level will give you 51.28-51.38
if specifically, the mean time to finish their standard test course should be less than 55 seconds for a former Olympic champion, then the null hypothesis is correct
Then;
Null hypothesis: mean <55
Alternative hypothesis :mean =55
represent Jose's drived distance and 
represent Rob's.
