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A random sample of 45 households was selected as part of a study on electricity usage.,...

A random sample of 45 households was selected as part of a study on electricity usage., and the number of kilowatt-hours (kWh) was recoded for each household. The average usage was found to be 375 kWh. The population standard deviation is given as 51 KWh Assuming the usage is normally distributed, find the margin of error for a 99% confidence interval for the mean. [3 marks] 12.5 14.9 19.6 22.8

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