Question

For a random sample of 20 students, the average score on a test was found to be 63.4 with a standard deviation of 12.34. Construct a 90% upper confidence bound

Answer 1

To construct a 90% upper confidence bound for the average score on a test, you can use the formula: Upper Confidence Bound = sample mean + (critical value * standard deviation). The upper confidence bound is approximately 83.39.

Step-by-step explanation:

To construct a 90% upper confidence bound, we can use the formula:

Upper Confidence Bound = sample mean + (critical value * standard deviation)

Given that the sample mean is 63.4 and the standard deviation is 12.34, we need to find the critical value for a 90% confidence level.

Looking up the critical value in a standard normal distribution table, we find that it is approximately 1.645. Plugging in the values into the formula:

Upper Confidence Bound = 63.4 + (1.645 * 12.34)

Upper Confidence Bound ≈ 83.39