Answer:
40 %
Step-by-step explanation:
30/85 = .4
.4 × 100 = 40 %
Using the z-distribution, it is found that the 90% confidence interval is given by: (0.6350, 0.6984).
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
In this problem, we have a 90% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.645.
The sample size and the estimate are given by:

Hence, the bounds of the interval are given by:


The 90% confidence interval is given by: (0.6350, 0.6984).
More can be learned about the z-distribution at brainly.com/question/25890103
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The total amount of calories burnt in jogging 2 miles = 185 calories
We have to determine the number of calories burned in jogging 3 miles.
Firstly, we will determine the amount of calories burnt in jogging 1 mile. We will use unitary method to evaluate this.
So, the total amount of calories burnt in jogging 1 mile = 
= 92.5 calories
So, the amount of calories burnt in 3 miles = 
= 277.5 calories
Therefore, 277.5 calories are burned in jogging 3 miles.
Using derivatives, it is found that the x-values in which the slope belong to the interval (-1,1) are in the following interval:
(-15,-10).
<h3>What is the slope of the tangent line to a function f(x) at point x = x0?</h3>
It is given by the derivative at x = x0, that is:
.
In this problem, the function is:

Hence the derivative is:

For a slope of -1, we have that:
0.4x + 5 = -1
0.4x = -6
x = -15.
For a slope of 1, we have that:
0.4x + 5 = 1.
0.4x = -4
x = -10
Hence the interval is:
(-15,-10).
More can be learned about derivatives and tangent lines at brainly.com/question/8174665
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Answer:
6x^2-28x+30
Step-by-step explanation: