Answer:
53.15≤x≤67.89
Step-by-step explanation:
The formula for calculating confidence interval is expressed as;
CI = xbar±(z×s/√n)
xbar is the sample mean
z is the z score at 90% CI
s is the standard deviation
n is the sample size
Given
xbar = $60.52
s = $23.29
n = 27
z = 1.645
Substitute into the formula
CI = xbar±(z×s/√n)
CI = 60.52±(1.645×23.29/√27)
CI = 60.52±(1.645×23.29/5.196)
CI = 60.52±(1.645×4.482)
CI = 60.52±7.373
CI = [60.52-7.373, 60.52+7.373]
CI = [53.15, 67.89]
Hence the 90% confidence interval for the mean repair cost for the refrigerators is 53.15≤x≤67.89
Answer:
y = 5
Step-by-step explanation:
if y = 5 then
(√10-1) -1 = 2
3 - 1 = 2
true
1/2 times 8 equals 4.
You multiply by 8 because the denominator is 8 so you have to have that recipe 8 times to get a whole.
X = 0 is the smallest x can be. Anything smaller and it wouldn't make any sense because negative time values make no sense.
x = 7 is the largest x can be. Why? Because plugging in x = 7 leads to
f(x) = 1575 - 225x
f(7) = 1575 - 225*7
f(7) = 1575 - 1575
f(7) = 0
so at year 7, the value is 0 dollars. Any x value larger than 7 will produce negative dollar values, which make no sense.
Another way to get x = 7 is to notice that 1575 - 225x = 0 has the solution x = 7
We'd solve for x like so
1575 - 225x = 0
1575 = 225x
225x = 1575
x = 1575/225
x = 7
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So x = 0 is the smallest x can be and x = 7 is the largest x can be. This means the domain is
Answer: Choice D