Answer:
(221.39, 300.61) and (255.2223, 266.7777)
Step-by-step explanation:
Given that X, the lengths of pregnancies in a small rural village are normally distributed with a mean of 261 days and a standard deviation of 17 days
Middle 98% would lie on either side of the mean with probability ±2.33 in the std normal distribution on either side of 0
Corresponding we have x scores as
Between
and 
i.e. in the interval = (221.39, 300.61)
If sample size = 47, then std error of sample would be

So 98% of pregnancies would lie between
and 
= (255.2223, 266.7777)
It’s A, I think not very sure
Answer:
a ^ (1/12)
Step-by-step explanation:
a ^ (1/3)
---------------
a ^ (1/4)
We know that b^ c / b^ d = b ^ (c-d)
a^ (1/3 - 1/4)
getting a common denominator
1/3 *4/4 - 1/4*3/3 = 4/12 - 3/12
a^ (4/12 - 3/12)
a ^ (1/12)
I've done this test before
The factor should be x+7 so, none of the above.
Hope I helped! ( Smiles )