Rechargeable Batteries
a Researcher Wants to Study the Average Lifetime $\mu$

Essay

Rechargeable Batteries
A researcher wants to study the average lifetime of a certain brand of rechargeable batteries (in hours).In testing the hypotheses,H₀: $\mu$ = 950 hours vs.H₁: $\mu$ $\neq$ 950 hours,a random sample of 25 rechargeable batteries is drawn from a normal population whose standard deviation is 200 hours.
-{Rechargeable Batteries Narrative} Recalculate $\beta$ if n is increased from 25 to 40.