The number of square feet per house are normally distributed with a population standard deviation of 137 square feet and an unknown population mean. a random sample of 19 houses is taken and results in a sample mean of 1350 square feet. find the margin of error for a 80% confidence interval for the population mean.

Step-by-step explanation:

Given that X, the number of square feet per house is N(mean, 137)

Sample size = 19

Sample mean x bar =1350 sq ft

Since population std dev is given,

std error of sample =

Since sample size is small, t critical value can be used

df = 18

t value for 80% two tailed = 1.333

Margin of error = ±1.333(std error) = ±

Confidence interval = sample mean ±margin of error

=

assuming you mean addition: addition and subtraction are reverse operations.

step-by-step explanation:

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step-by-step explanation: