Answer:
atleast 385
Step-by-step explanation:
Given that an electrical power company is looking to expand into a new market. Before they commit to supplying the new area with electricity, they would like know the mean daily power usage for homes there.
Population std deviation =
Sample size =
STd error of sample mean =
Margin of error for 95% would be Critical value ( std error)
Here since population std dev is known we can use Z critical value= 1.96
Sample size should be atleast 385