Answer and Step-by-step explanation:
The area formula for a Circle is:
A =
Diameter is equal to the radius times 2.
<u>So, divide the diameter to get the radius.</u>
6 divided by 2 equals 3.
<u>Now, plug it into the formula.</u>
A =
Plug this into your calculator by multiplying 9 by pi.
<u>We get the answer to be 28.3 when rounded to the nearest tenth.</u>
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<em><u>#teamtrees #PAW (Plant And Water)</u></em>
Answer:
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.064
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 81.5 - 4.21 = 77.29
The upper end of the interval is the sample mean added to M. So it is 81.5 + 4.21 = 85.71.
The 90% confidence interval for the mean test score is between 77.29 and 85.71.