population mean using the Student’s t-distribution

Calculate the margin of error and construct the confidence interval for the population mean using the Student’s t-distribution (you may assume the population data is normally distributed).
T-Distribution Table
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a. x̄ =88.7, n=68, s=12.9, 95% confidence
E=

Round to two decimal places if necessary
< μ < Round to two decimal places if necessary ________________________________________ b. x̄ =39.5, n=45, s=12.6, 90% confidence E= Round to two decimal places if necessary < μ < Round to two decimal places if necessary