Answer:
The 90% confidence interval is
Step-by-step explanation:
From the question we are told that
The sample size is n = 64
The sample mean is
The standard deviation is
Given that the confidence interval is 90% then the level of significance is mathematically evaluated as
Next we obtain the critical value of from the normal distribution table , the value is
Generally the margin of error is mathematically represented as
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The 90% confidence interval is mathematically represented as
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