The lifespan, $L$ (in months) of the battery in a certain brand of handphone is normally distribut

Question

The lifespan, $L$ (in months) of the battery in a certain brand of handphone is normally distributed. It is known that $21\%$ of the batteries last for more than $26$ months and $34\%$ of the batteries last for less than $23$ months. Find the mean and variance of $L$.[4]

Accepted Answer

mean = 24.0, variance = 6.06

2024 RI H1 Q6

2024 RI H1 Q6