In: Statistics and Probability
A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $54.
a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $47? (Use .10 level of significance.) State the null and alternative hypotheses.
b. Identify the critical values.
c. Determine the test statistic.
d. Do Not Reject/Reject H0. there is Insufficient/Sufficient evidence that the population mean spent by membership member customer is different from $47.
e. Determine the p-value and interpret its meaning.
Solution :
= 47
= 55
S = 54
n = 100
a ) This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 47
Ha : 47
b ) The significance level is α =0.10, and the critical value for a two-tailed test is tc = 1.66
c ) Test statistic = t
= ( - ) / S / n
= (55 - 47) / 54 / 100
= 1.481
Test statistic = t = 1.481
P-value =0.1417
= 0.10
P-value <
0.1417 ≥ 0.10
d )Fail to reject the null hypothesis .
e )There is insufficient evidence that the population mean spent by membership member customer is different from $47.