Answer:
a. n=4148
b. n=3909
c. The sample size is smaller if a known proportion from prior study is used. The difference in sample sizes is 239
Step-by-step explanation:
a. For sample where no preliminary estimate is given, the minimum sample size is calculated using the formula:

Where:
Margin of error
is the assumed proportion
#Let p=0.5, substitute in the formula to solve for n:

Hence, the minimum sample size is 4148
b. If given a preliminary estimate p=0.38, we use the same formula but substitute p with the given value:

Hence, the minimum sample size is 3909
c. Comparing the sample sizes from a and b:

Hence, the actual sample size is smaller for a known proportion from prior a prior study.
In an installment loan, a lender loans a borrower a principal amount P, on which the borrower will pay a yearly interest rate of i (as a fraction, e.g. a rate of 6% would correspond to i=0.06) for n years. The borrower pays a fixed amount M to the lender q times per year. At the end of the n years, the last payment by the borrower pays off the loan.
After k payments, the amount A still owed is
<span>A = P(1+[i/q])k - Mq([1+(i/q)]k-1)/i,
= (P-Mq/i)(1+[i/q])k + Mq/i.
</span>The amount of the fixed payment is determined by<span>M = Pi/[q(1-[1+(i/q)]-nq)].
</span>The amount of principal that can be paid off in n years is<span>P = M(1-[1+(i/q)]-nq)q/i.
</span>The number of years needed to pay off the loan isn = -log(1-[Pi/(Mq)])/(q log[1+(i/q)]).
The total amount paid by the borrower is Mnq, and the total amount of interest paid is<span>I = Mnq - P.</span>
Answer:
Step-by-step explanation:
Answer: k = -1 +/- √769
<u>Step-by-step explanation:</u>
48x - ky = 11
<u>-48x </u> <u> -48x</u>
-ky = -48x + 11
Slope:
*************************************************************************
(k + 2)x + 16y = -19
<u>- (k + 2)x </u> -<u>(k + 2)x </u>
16y = -(k + 2)x - 19


Slope: 
**********************************************************************************
and
are perpendicular so they have opposite signs and are reciprocals of each other. When multiplied by its reciprocal, their product equals -1.
*
= -1
= 1
Cross multiply, then solve for the variable.
(k + 2)(k) = 16(48)
k² + 2k - 768 = 0
Use quadratic formula to solve:
k = -1 +/- √769