He lengths of a particular animal's pregnancies are approximately normally distributed, with mean muequals252 days and standard deviation sigmaequals20 days. (a) What proportion of pregnancies lasts more than 262 days? (b) What proportion of pregnancies lasts between 227 and 257 days? (c) What is the probability that a randomly selected pregnancy lasts no more than 237 days? (d) A "very preterm" baby is one whose gestation period is less than 202 days. Are very preterm babies unusual?

Step-by-step explanation:

Let X be the lengths of a particular animal's pregnancies

X is N(252, 20)

(a) What proportion of pregnancies lasts more than 262 days?

(b) What proportion of pregnancies lasts between 227 and 257 days?

(c) What is the probability that a randomly selected pregnancy lasts no more than 237 days?

P(X<237) = 0.2266

(d) A "very preterm" baby is one whose gestation period is less than 202 days. Are very preterm babies unusual?

Yes very unusual since probability is very near to 0.

d

step-by-step explanation:

d

$3720

step-by-step explanation:

taxable income = $31000

as per the 2018-2019 us tax bracket, the tax rate is 12% for an individual whose taxable income is between $9,526 to $38,700.

so, the tax to be paid by him = 12% of 31000

= 0.12 * 31000     [12% converted to decimal as 0.12]

= $3720