Final answer:
To construct a 98% confidence interval for the average amount of sleep students at this university got last night, use the formula: Confidence Interval = sample mean ± (critical value * standard deviation/square root of sample size). In this context, we can be 98% sure that the mean amount of sleep students at this university got last night falls between 6.44 and 7.26 hours.
Step-by-step explanation:
To construct a 98% confidence interval for the average amount of sleep students at this university got last night, we can use the formula: Confidence Interval = sample mean ± (critical value * standard deviation/square root of sample size).
First, we need to find the critical value for a 98% confidence level. Since the sample size is large (148), we can use the Z-score table. The critical value for a 98% confidence level is approximately 2.33.
Plugging in the values into the formula, we get: Confidence Interval = 6.85 ± (2.33 * 2.12/square root of 148). Simplifying the expression, we get the confidence interval of (6.44, 7.26).
In this context, it means that we can be 98% sure that the mean amount of sleep students at this university got last night is between 6.44 and 7.26 hours.