We would need a sample size of 560.
We first calculate the z-score associated. with this level of confidence:
Convert 95% to a decimal: 95% = 95/100 = 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2: 0.05/2 = 0.025
Subtract from 1: 1-0.025 = 0.975
Using a z-table (http://www.z-table.com) we see that this is associated with a z-score of 1.96.
The margin of error, ME, is given by:

We want ME to be 4%; 4% = 4/100 = 0.04. Substituting this into our equation, as well as our proportion and z-score,
Answer:
Diverges
Step-by-step explanation:
We can solve this by using integral by parts:
Let



We can add
to both sides

We can evaluate the limit between 2 and infinity.
If x tends to infinity the limit will be infinity and therefore the integral diverges to ∞
Answer:
Grade B score:
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 73.3
Standard Deviation, σ = 9.7
We are given that the distribution of score on test is a bell shaped distribution that is a normal distribution.
Formula:

B: Scores below the top 5% and above the bottom 62%
We have to find the value of x such that the probability is 0.62
Calculation the value from standard normal z table, we have,
We have to find the value of x such that the probability is 0.05

Calculation the value from standard normal z table, we have,
Thus, the numerical value of score to achieve grade B is

Answer:
56x6+3x
Step-by-step explanation:
3x+7x(8x5)
3x+56x6
Answer:
18 boys
Step-by-step explanation:
boys/girls = 3/11 = b/66
3/11 = b/66
11b = 3 × 66
b = 3 × 6
b = 18
There are 18 boys.