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In: Statistics and Probability

Mean systolic blood pressure is 120 for a sample of 20 individuals, with a population standard...

Mean systolic blood pressure is 120 for a sample of 20 individuals, with a population standard deviation of 15. Calculate a 95% confidence interval. Round the answer to the 1(one) decimal place

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Expert Solution

Solution :

Given that,

= 120

= 15

n = 20

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96

Margin of error = E = Z/2* ( /n)

= 1.96 * (15 / 20)

= 6.6

At 95% confidence interval estimate of the population mean is,

- E < < + E

120 - 6.6 < < 120 + 6.6

113.4 < < 126.6

(113.4 , 126.6)

orchestra answered 3 years ago
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