Question

Suppose the mean height in inches of all 9th grade students at one high school is estimated the population standard deviation is 4 inches the height of 7 randomly selected students are 69,74,66,66,62,64,and 74 what is the margin of error at 99% confidence level

Answer 1

1.474

Explanation:

Given that :

Population standard deviation, σ = 4

Sample size = 7

Confidence level = 99%

Since we ore using the population standard deviation, the we use the Z distribution table:

The margin of error :

Zcritical * σ/√n

Zcritical at 99% = 2.58

The margin of error :

2.58 * 4/√7

2.58 * 0.5714285

= 1.474