I was hoping someone would understand this better than I do. I am trying to solve the following problem:

**We are testing the hypothesis that the average gas consumption per day in Billings, Montana is greater than 7 gallons per day; we want 95% confidence.**

We sample 30 drivers. The average is 8.4, and the sample standard deviation is 4.29. Our null hypothesis is H0:μ≤7

1) What is the Z-value for our sample mean of 8.4?

2) What is the p-value for our sample mean of 8.4?

3) Do we reject the null hypothesis?

We sample 30 drivers. The average is 8.4, and the sample standard deviation is 4.29. Our null hypothesis is H0:μ≤7

1) What is the Z-value for our sample mean of 8.4?

2) What is the p-value for our sample mean of 8.4?

3) Do we reject the null hypothesis?

Now, my first reaction is to use the z-score formula for converting sample mean: z = (x – μ) / (σ / √n), but I don't seem to have all the data required for this, since there is just one mean given. I can't figure out what I am missing! I don't expect a calculation for me (obviously!), but could someone lead me to the right way of calculating this? Many thanks in advance!