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 ≥ ![[Z_\alpha_/_2 * (\frac{\sigma}{ME})]^2](https://tex.z-dn.net/?f=%20%5BZ_%5Calpha_%2F_2%20%2A%20%28%5Cfrac%7B%5Csigma%7D%7BME%7D%29%5D%5E2%20)
n ≥ ![[1.64 * (\frac{475}{100})]^2](https://tex.z-dn.net/?f=%5B1.64%20%2A%20%28%5Cfrac%7B475%7D%7B100%7D%29%5D%5E2)
n ≥ 60.68
≈ 61
Minimun sample size,n = 61
Answer:
12 sq. ft.
Step-by-step explanation:
A=1/2bh
triangle 1: 1/2x2x4=4
triangle 2: 1/2x4x4=8
4+8=12
3√35-simplest radical form
Let
x------> hours worked by Sara last week
y------> hours worked by Joan last week
z------> hours worked by Erin last week
we know that
x=28 hours ------> equation 1
y=x-6-----> equation 2
substitute the value of x in equation 2
y=28-6=22 hours
z=y/2------> equation 3
substitute the value of y in the equation 3
z=22/2=11 hours
<u>the answer is</u>
Sara worked 28 hours last week
Joan worked 22 hours last week
Erin worked 11 hours last week
