Step 1 :First, we need to calculate the standard error, which is the standard deviation divided by the square root of the sample size. In this case, the standard deviation is 7 and the sample size is 51. So, the standard error is \( \frac{7}{\sqrt{51}} \approx 0.9802 \).
Step 2 :Next, we need to calculate the z-score, which is \( \frac{value - mean}{standard \, error} \). The value is 40.6, the mean is 40, and the standard error is 0.9802. So, the z-score is \( \frac{40.6 - 40}{0.9802} \approx 0.6121 \).
Step 3 :Finally, we need to use a z-table to find the probability that the sample mean would be less than 40.6 dollars. The z-score is 0.6121, so the probability is approximately 0.7298.
Step 4 :\(\boxed{0.7298}\) is the final answer, which is the probability that the sample mean would be less than 40.6 dollars.