Answer:
Step-by-step explanation:
Given that the mean incubation time (say X) for a type of fertilized egg kept at 100.9°F is 21 days.
X is N( 21,1)
a) the probability that a randomly selected fertilized egg hatches in less than 19 days
=[tex]P(X<19) = P(Z<\frac{19-21}{1} \\=P(Z<-2) \\=0.02275[/tex]
b) the probability that a randomly selected fertilized egg takes over 23 days to hatch
=P(X>26) = 0.000
(almost uncertain event)
c) the probability that a randomly selected fertilized egg hatches between 20 and 21 days
= F(21)-F(20) = 0.341345
d) Let us find prob P(X<18)
= 0.00135
Yes, unusual because probability is very less and near to 0
