Laboratory experiment shows that the life of the average butterfly is normally distributed with a mean of 18.8 days and a standard deviation of 2 days.

find the probability that a butterfly will live between 12.04 and 18.38 days.

a) 0.4164

b) 0.4203

c) 0.5828

d) 0.3893

e) 0.4202

f) none of the above.

a) 0.4164

Step-by-step explanation:

Mean lifespan (μ) = 18.8 days

Standard deviation (σ) = 2 days

For any given lifespan 'X', the z-score is:

For X=12.04 days:

A z-score of -3.38 falls in the 0.036-th percentile of a normal distribution.

For X=18.38 days:

A z-score of -3.38 falls in the 41.68th percentile of a normal distribution.

The probability that a butterfly lives between 12.04 and 18.38 days is

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^