Look carefully at the diagram. The shaded region represents 3/4 of the total area of the circle, which, in turn, is pi*r^2, or pi*(8 cm)^2.
Thus, the area of the shaded region is (3/4)*pi*(64 cm^2), or 48 pi cm^2.
Answer with step-by-step explanation:
The way the question is worded, this actually shouldn't be correct. The correct answer should be
.
Because the trapezoids are similar, we can find the ratio of their perimeters by actually just finding the ratio of their sides.
Why?
By definition, the corresponding sides of a polygon are in a constant proportion. The perimeter is simply the sum of all sides of the polygon. Since we're just adding the sides, the proportion will still be maintained.
Therefore, we'll just need to ratio of their corresponding sides. The only two corresponding sides that are marked are
and
.
The ratio of
is
.
The reason why it ideally should be
and not
is because the question states
, which mentions
first, so our answer should follow this respective order. I believe you were marked right anyways because the specific order is not specified, but generally, you want to give your answer respectively by default.
As described in z-distribution the answers are given below:
a) The 95% confidence interval estimate for the population mean spending by a customer on visiting salon per month is given as follows: (747, 853).
b) The sampling error at 95% confidence level is of: $35.78.
What is a z-distribution ?
The normal distribution with a mean of 0 and a standard deviation of 1 is referred to as the standard normal distribution (also known as the Z distribution) (the green curves in the plots to the right). It is frequently referred to as the bell curve since the probability density graph resembles a bell.
solution:
The bounds of the confidence interval are given as follows:
In which:
is the sample mean.
z is the critical value.
n is the sample size. is the standard deviation for the population.
The parameters for this problem are given as follows:
Hence the lower bound of the interval is of:
800 - 200 x 1.96/square root of 55 = 747.
The upper bound of the interval is of:
800 + 200 x 1.96/square root of 55 = 853.
The sampling error for a sample size of 120 is calculated as follows:
200 x 1.96/square root of 120 = $35.78.
To learn more about the z-distribution from the given link
brainly.com/question/4079902
#SPJ1
Answer: 15.7 minutes
Step-by-step explanation:
Let x be the time in the beginning (in minutes).
Given: The track team is trying to reduce their time for a relay race.
First they reduce their time by 2.1 minutes.
Then they are able to reduce that time by 10
If their final time is 3.96 minutes, then
x-t1-t2= 3.6
x= 3.6+ t1+ t2
x= 3.6+ 2.1+ 10
x= 15.7
Hence, their beginning time was 15.7 minutes.
Answer:
Bob forgot to distribute 3 to 1.50 in the parentheses
Step-by-step explanation:
Bob made the mistake in his first step.
In the equation 3(x + 1.50) = 30, the 3 has to be distributed to both x and 1.50.
But, Bob only distributed it to x, which led him to get the wrong answer.
So, Bob's mistake when solving was that he forgot to distribute the 3 to 1.50