This breaks into two inequalities:
2x - 3 > 6
and
-2x + 3 > 6
------------------------
2x - 3 > 6
Add 3 to both sides:
2x > 9
Divide 2 to both sides:
x > 4.5
-----------------------
-2x + 3 > 6
Subtract 3 to both sides:
-2x > 3
Divide -2 to both sides:
x < -1.5
22 quarters= $5.50
10 dimes= $1.00
$5.50 + $1.00 = $6.50
I just did trial and error. I started with 20 quarters and made changes until it worked.
Answer:
we will fail to reject the null hypothesis and conclude that the return rate is less than 20%.
Step-by-step explanation:
We are given;
Sample size;n = 6970
Success rate;X = 1334/6970 = 0.1914
Now, we want to test the claim that the return rate is less than p = 0.2, hence the null and alternative hypothesis are respectively;
H0: μ < 0.2
Ha: μ ≥ 0.2
The standard deviation formula is;
σ = √(x(1 - x)/n)
σ = √(0.1914(1 - 0.1914)/6970)
σ = 0.004712
Now for the test statistic, formula is;
z = (x - μ)/σ
z = (0.1914 - 0.2)/0.004712
z = -1.825
From the a-distribution table attached, we have a value of 0.03362.
This p-value gotten from the z-table is more than the significance value of 0.01. Thus, we will fail to reject the null hypothesis and conclude that the return rate is less than 20%.
