Answer:

Step-by-step explanation:

Identity used:


Now let us divide the modified expressions:
÷ 
we get:

Answer:
12.90= .90+ 2x
12=2x
6=x
Each bag of books cost was $6
Answer:
See explanation below
<u>Step-by-step explanation:</u>
range = 2200 - 300 = 1900
To find standard deviation, we have:
standard deviation = range/4 =
= 475
The range rule of thumb estimate for the standard deviation is 475
Given:
Standard deviation,
= 475
Margin of Error, ME = 100
= 1 - 0.90 = 0.10
Za/2 = Z0.05 = 1.64
Find sample size, n:
n ≥
n ≥
n ≥ 60.68
≈ 61
Minimun sample size,n = 61
Step by step in the picture
Okay. 40% of 50 is 20. 2 * 20 is 40. The other 30 tables seat 4 people. 4 * 30 is 120. 120 + 40 is 160. There are 160 seats in the restaurant.