(x+2)(x+1)
If you multiply those together then it will equal x^2+3x+2.
The lengths of pregnancies are normally distributed with a mean of 266 days and a standard deviation of 15 days.
That is,
Consider X be the length of the pregnancy
Mean and standard deviation of the length of the pregnancy.
Mean 
Standard deviation \sigma =15
For part (a) , to find the probability of a pregnancy lasting 308 days or longer:
That is, to find 
Using normal distribution,



Thus 
So 




Thus the probability of a pregnancy lasting 308 days or longer is given by 0.00256.
This the answer for part(a): 0.00256
For part(b), to find the length that separates premature babies from those who are not premature.
Given that the length of pregnancy is in the lowest 3%.
The z-value for the lowest of 3% is -1.8808
Then 
This implies 
Thus the babies who are born on or before 238 days are considered to be premature.
This is how you would arrive to the answer 37
Answer:
2
Step-by-step explanation u answer is 2