#### Answer

a)1.766
b)3.01.
c)3.01
d)Not usual.

#### Work Step by Step

a) Difference between the magnitude of the strongest earthquake and the mean magnitude: $2.95-1.184=1.766.$
b)$z=\frac{x-\mu}{\sigma}=\frac{2.95-1.184}{0.584}=3.01.$
Hence the magnitude of the strongest earthquake is 3.01 standard deviations from the mean magnitude.
c))$z=\frac{x-\mu}{\sigma}=\frac{2.95-1.184}{0.584}=3.01.$
d) The strongest earthquake's z-score is not between -2 and 2, hence it is not usual.