In: Statistics and Probability
According to Sallie Mae, students graduating from college have an average credit card more than $4150. In a random sample of 50 graduating seniors the average credit card debt was $4500 and the standard deviation was $1200. Do the evidence support Sallie Mae’s claim?
Set up the null and alternate hypotheses to test Sallie Mae’s claim.
Compute an appropriate test statistic.
What is the p-value? Conclude at α = 0.05. Explain.
H0: = 4150
H1: > 4150
The test statistic t = ()/(s/)
= (4500 - 4150)/(1200/)
= 2.06
P-value = P(T > 2.06)
= 1 - P(T < 2.06)
= 1 - 0.9776
= 0.0224
Since the P-value is less than the significance level(0.0224 < 0.05),we should reject the null hypothesis.
So there is sufficient evidence to support Sallie Mae's claim that students graduating from college have an average credit card more than $4150