In: Statistics and Probability
A seafood restaurant often receives complaints from it’s patrons that the lobster is too small. The menu lists the weight of a lobster as 462g. The next time the restaurant receives a batch of 60 lobsters it weighs them and finds the average is 451g with a standard deviation of 31g. Do you think the restaurant sells lobsters that are smaller than advertised? Perform a hypothesis test at α = 0.01
Population mean: = 462,
Sample size: n= 60,
Sample mean: = 451,
Sample standard deviation: s = 31
Significance level: = 0.01
null and alternative hypothesis is
Ho: = 462
Ha: < 462
formula for test statistics is
t = -2.749
test statistics: t = -2.749
now calculate P-Value for this one tailed test with df= n-1 = 60 - 1 = 59
using following excel command we get p-value as,
P-Value = 0.0040
decision rule is,
Reject Ho if (P-Value) < ( )
Here, ( P-Value = 0.0040 ) < ( = 0.01 )
Hence,
Null hypothesis is rejected.
Therefore there is sufficient evidence to conclude that the restaurant sells lobsters that are smaller than advertised weight of 462.