Answer:
0.5466
Step-by-step explanation:
Given that the length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 266 days and standard deviation 16 days.
Let X be the length of pregnancies
X is N(266,16)
To find out the probability that pregnancies last between 240 and 270 days (roughly between 8 months and 9 months)
P(240<x<270)
convert each into Z score as 
x=240 means Z = -1.625
x=270 means z=0.25
Required prob
= 
Answer:
3n + 2
Step-by-step explanation:
Answer is in the file below
tinyurl.com/wpazsebu
Summation of 3n + 2 from n = 1 to n = 14 = (3(1) + 2) + (3(2) + 2) + (3(3) + 2) + . . . + (3(14) + 2) = 5 + 8 + 11 + ... + 44 ia an arithmetic progression with first term (a) = 5, common difference (d) = 3 and last term (l) = 44 and n = 14
Sn = n/2(a + l) = 14/2(5 + 44) = 7(49) = 343
Therefore, the required summation is 343.