The lengths of pregnancy terms for a particular species of mammal or nearly normally distributed about a mean pregnancy length with a standard deviation of 10 days about what percentage of births would be expected to occur within 20 days of the mean pregnancy length

the first one

step-by-step explanation:

just id the test.

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %