Answer: (80% , 85%)
Step-by-step explanation:
We know that, confidence interval for population proportion is given by :-
(p-E , p+E)
, where p = sample proportion , E = Margin of error.
Given : Proportion of elementary school teachers who are female = 82%.
The article also states the maximum error of their estimate = 3%.
Then, the 90% confidence interval for the proportion of elementary school teachers who are female will be :
(82%-2% , 82%+3%)
= (80% , 85%)
Hence, the resulting 90% confidence interval for the proportion of elementary school teachers who are female = (80% , 85%)
Answer:
a) 0.997 is the probability that the breaking strength is at least 772 newtons.
b) 0.974 is the probability that this material has a breaking strength of at least 772 but not more than 820
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 800 newtons
Standard Deviation, σ = 10 newtons
We are given that the distribution of breaking strength is a bell shaped distribution that is a normal distribution.
Formula:
a) P( breaking strength of at least 772 newtons)
Calculation the value from standard normal z table, we have,

0.997 is the probability that the breaking strength is at least 772 newtons.
b) P( breaking strength of at least 772 but not more than 820)

0.974 is the probability that this material has a breaking strength of at least 772 but not more than 820.
Answer:
Yes the sample can be use to make inference
Step-by-step explanation:
The inference is possible if the conditions:
p*n > 10 and q*n > 10
where p and q are the proportion probability of success and q = 1 - p
n is sample size
Then p = 12 / 30 = 0,4 q = 1 - 0,4 q = 0,6
And p*n = 0,4 * 30 = 12 12 > 10
And q*n = 0,6 * 30 = 18 18 > 10
Therefore with that sample the conditions to approximate the binomial distribution to a Normal distribution are met
Step-by-step explanation:
The given objective function is 
To check that which ordered pair is minimizing the objective function-we will substitute all the ordered pair one by one in the given function and we will calculate the value of C. The ordered pair which will give the minimum value will be the answer.
For (0, 160)

For (55, 70)

For (80, 50)

For (80, 50)

Hence the ordered pair which minimizes the objective function is (80, 50)
Answer:
$4.081
Step-by-step explanation:
We have been given that Melissa owns a credit card with a 8.9% APR. The balance after her last billing cycle was $550.
First of all, we will find period rate by dividing APR by 12 as 1 years equals 12 months.

The finance charge would be 0.74166% of $550.

Therefore, the finance charge would be $4.081.