Answer:
The average weekly grocery bill per four-person family in the town is significantly different from the national average.
Explanation:
We are given the following in the question:
Population mean, μ = $100
Sample mean,
= $103.23
Sample size, n = 25
Alpha, α = 0.05
Sample standard deviation, s = $8.82
First, we design the null and the alternate hypothesis
We use Two-tailed t test to perform this hypothesis.
Formula:
Putting all the values, we have
Now,
Since,

We accept the null hypothesis.
We accept the null hypothesis and determine that the average weekly grocery bill per four-person family in the town is significantly same to the national average.