Question

what is the 95% confidence interval for the mean. enter the margin of error only

119.4, 98.6, 117.5, 102.0 and 110.0

show the process

Answer 1

First, we will calculate the mean and standar deviation for the given sample

Mean = (sum of all values)/(total number of values) = (119.4+98.6+117.5+102+110)/5 = 109.5

Standard deviation =

where xi are given data values and x(bar) is the mean value = 109.5 and n is the sample size = 5

setting the values, we get

standard deviation =

this gives us

SD =

z score for 95% confidence interval is 1.96 (using z distribution critical value table)

Using the confidence interval formula

this gives us  

so, Confidence interval = (101.453, 117.547)

Margin of error is 8.05