Answer:
The calculated value Z = 1.4460 < 1.96 at 0.05 level of significance.
The null hypothesis is accepted
A local power company believes that residents in their area use more electricity on average than EIA's reported average
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Given that the mean of the Population = 10,608 kWh of electricity this year.
Given that the size of the sample n = 187
Given that mean of sample x⁻ = 10737 kWh
The Standard deviation of the Population = 1220kWh
Level of significance = 0.05
The critical value (Z₀.₀₅)= 1.96
<u><em>Step(ii):-</em></u>
Null Hypothesis: H₀:μ > 10608 kWh
Alternative Hypothesis: H₁: μ < 10608kWh
Test statistic
Z = 1.4460
<u>Final answer:-</u>
The calculated value Z = 1.4460 < 1.96 at 0.05 level of significance.
The null hypothesis is accepted
A local power company believes that residents in their area use more electricity on average than EIA's reported average.