Consider the population of electric usage per month for houses. The standard deviation of this population is 128 kilowatt-hours. What is the smallest sample size to provide a 90% confidence interval for the population mean with a margin of error of 30 or less

50

Step-by-step explanation:

Formula for sample size(n) if population standard deviation is known:

, E = Margin of error , =  Critical z-value

As per given,

kilowatt-hours.

Critical z-value for 90% confidence = 1.645

E =  30

Required sample size :

Hence,  the smallest sample size to provide a 90% confidence interval for the population mean with a margin of error of 30 or less = 50

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a)contains an infinite number of points b) can be used to create other geometric shapes c)describes something that does not have width or depth d) is a term that does not have a formal definition. a line is an undefined term because it: contains an infinite number of points.