The lifetime, in hours, of two brands of batteries have the following population parameters. MeanSta

Question

The lifetime, in hours, of two brands of batteries have the following population parameters.

	Mean	Standard Deviation
PowerX	$498$	$0.34$
EnergyZ	$501$	$0.21$

$80$ PowerX and $50$ EnergyZ batteries are selected at random.

Find the probability that the difference in the mean lifetimes of the $2$ brands of batteries is greater than $2.9$ hours.

Accepted Answer

$0.981\text{ (3 s.f.)}$

Sampling From A Non-Normal Population (Central Limit Theorem) Q7