Answer:
addition and multiplication
Step-by-step explanation:
add 4.5 + 1.5 to get 6 ft and then multiply that by 7
Answer:
x₁ = - 5, x₂ = 5
Step-by-step explanation:
x^2 + 3 = 28
x^2 = 28 - 3
x^2 = 25
x = ± 5
x = - 5
x = 5
Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
For this problem, we have that:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Answer:
radius=8
Step-by-step explanation:
Let the width be w, then length = 2w - 1
Area = length times width = w(2w - 1) = 21.
Thus, 2w^2 - w = 21 or 2w^2 - w - 21 = 0
Solving the quadratic equation gives that w = 3.5.
Therefore, width is 3.5 ft and length is 2(3.5) - 1 = 6 ft.