Question 1185303
Here's how to calculate the required sample size:

1. **Identify the key values:**

*   Confidence level = 90%  This means α = 1 - 0.90 = 0.10. Since we're dealing with a confidence interval, we need to split alpha into two tails to find the z-score. α/2 = 0.05
*   Margin of error (E) = 1 minute
*   Standard deviation (σ) = 3.4 minutes

2. **Find the z-score:**

For a 90% confidence level, the z-score corresponding to α/2 = 0.05 is 1.645. You can find this using a z-table or a calculator with statistical functions.

3. **Use the sample size formula:**

The formula for calculating the sample size (n) is:

n = (z * σ / E)²

4. **Plug in the values and calculate:**

n = (1.645 * 3.4 / 1)²
n = (5.593 / 1)²
n = 31.28

5. **Round up to the nearest whole number:**

Since you can't have a fraction of a subject, always round the sample size *up* to the next whole number.  Therefore, you would need 32 subjects.