The 95% confidence interval estimate of the population mean is between $50,555.51 and $51.444.49.
Confidence interval is defined as the range of values where a parameter might fall at a given confidence level. It can be calculated using the formula below.
CI = μ ± z x (SD / √n)
where CI = confidence interval
μ = sample mean
z = found by using a z-score table
SD = sample standard deviation
n = sample size
At 95% confidence level, the area in each tail of the standard normal curve is 2.5, and the cumulative area up to the second tail is 97.5.
(100 - 95) / 2 = 2.5
100 - 2.5 = 97.5
Find 0.975 in the z-table to get the value of z.
At p = 0.95, z = 1.96
Plug in the values and solve for the confidence interval.
CI = μ ± z x (SD / √n)
CI = $51,000 ± 1.96 x ($1,200 / √28)
CI = $51,000 ± $444.49
CI = [$50,555.51, $51.444.49]
Learn more about confidence interval here: brainly.com/question/15905481
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