What exactly are you looking for? Do you want the answer to all of them?
Answer:

Step-by-step explanation:
The firm tests 75 parts, and finds that 0.25 of them are notusable
n = 75
x = 0.25 \times 75 = 18.75≈19



Confidence level = 95%
So, Z_\alpha at 95% = 1.96
Formula of confidence interval of one sample proportion:


Confidence interval 
Answer:
a) 
b) The balance after 8 years will be of $29,069.
Step-by-step explanation:
Compound interest:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
a)
Loan of $17,500 means that 
6.4% interest rate means that 
Compounded monthly means that
. So



b)
This is A(8). Then

The balance after 8 years will be of $29,069.
Answer: Cool
Step-by-step explanation:
Greg is working on a school project
Yes....because a terminating decimal can be turned into a fraction, making it rational