Question

A random sample of size 100 was taken from a population. A 94% confidence interval to estimate the mean of the population was computed based on the sample data. The confidence interval for the mean is: (107.62,129.75). What is the z-value that was used in the computation

Answer 1

The z-value used in the computation of the confidence interval is -1.88.

Step-by-step explanation:

To find the z-value used in the computation of the confidence interval, we need to know the confidence level associated with the interval. Since a 94% confidence interval is given, we can determine the z-value by subtracting the confidence level from 1 and dividing the result by 2 to find the area in the tails of the standard normal distribution.

For a 94% confidence interval, the area in the tails is (1 - 0.94) / 2 = 0.03. We can then use a standard normal distribution table or calculator to find the z-value that corresponds to an area of 0.03 in the tails. This z-value is approximately -1.88.

Therefore, the z-value that was used in the computation of the confidence interval is -1.88.