The electric cooperative needs to know the mean household

Last updated: 10/8/2023

The electric cooperative needs to know the mean household usage of electricity by its non commercial customers in kWh per day They would like the estimate to have a maximum error of 0 15 kWh A previous study found that for an average family the standard deviation is 2 5 kWh and the mean is 15 9 kWh per day If they are using a 85 level of confidence how large of a sample is required to estimate the mean usage of electricity Round your answer up to the next integer