The z-statistic for Brett's data is found to be as given by: Option A: -5.30 (approx).
<h3>How to find the value of z-statistic for population mean?</h3>
Suppose we're specified that:
- The sample mean =

- The population mean =

- The population standard deviation =

- The sample size = n
Then the z-statistic for this data is found as:

For this case, we've got:
- The sample mean =
= 295 - The population mean =
= 310 - The population standard deviation =
= 20 - The sample size = n = 50
Thus, we get:

Thus, the z-statistic for Brett's data is found to be as given by: Option A: -5.30 (approx).
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