Answer:
a) 81.5%
b) 95%
c) 75%
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 266 days
Standard Deviation, σ = 15 days
We are given that the distribution of length of human pregnancies is a bell shaped distribution that is a normal distribution.
Formula:

a) P(between 236 and 281 days)

b) a) P(last between 236 and 296)

c) If the data is not normally distributed.
Then, according to Chebyshev's theorem, at least
data lies within k standard deviation of mean.
For k = 2

Atleast 75% of data lies within two standard deviation for a non normal data.
Thus, atleast 75% of pregnancies last between 236 and 296 days approximately.
Answer:
1.425
Step-by-step explanation:
b.0.76
0.76÷1000=0.076
l425÷1000=1.425
Answer:
1/12
Step-by-step explanation:
Given that
30/360 to lowest fraction equivalent
Now, we can write 30 as 3×10
Also, we can write 360 as 36×10
Then, we have
(3×10)/(36×10)
Then, 10 cancel 10, we are left with
3/36
Also we can write 36 as 12×3
Then, we have
3/(12×3)
Also, 3 cancel 3, we are left with
1/12
Then the lowest fraction is 1 / 12
1/12
In a line with negative slope, as x increase, y decreases.