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3 years ago

Can someone explain the steps to finding the perimeter of a semi-circle? I didn't really understand it during class. Thanks

Mathematics

1 answer:

andriy [413]3 years ago

6 0

We know that the perimeter of a cylinder is 2πr we will find it as we do always. The perimeter will be :
2 pi r
= 2 pi * 20
= 40 pi
Because it says rounded to the nearest tenth the answer will be : 125.6 cm^3
Because we have a half of a cylinder we will just divide the answer we got by 2:
125.6cm^3 /2 =62.8
The answer is 62.8 cm^3

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3 years ago

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This question is incomplete, the complete question is;

Suppose John is a high school statistics teacher who believes that watching many hours of TV leads to lower test scores. Immediately after giving the most recent test, he surveyed each of the 24 students in his class and asked them how many hours of TV they watched that week. He then matched each student's test grade with his or her survey response. After compiling the data, he used hours of TV watched to predict each student's test score. He found the least-squares regression line to be y" = -1.5x + 85.

He also calculated that the value of r, the correlation, was -0.61.

what is the correct value of the coefficient of determination R² and give a correct interpretation of its meaning

Answer:

Interpretation of coefficient of determination R² = 0.3721

R² = 0.3721, meaning 37.21% of the total variation in test scores can be explained by the least square regression line

Step-by-step explanation:

Given the data in the question;

the least square regression line is;

y" = -1.5x + 85

the correlation coefficient r = -0.61

Now, the coefficient of determination R² is square of correlation coefficient r

R² = -61²

R² = 0.3721

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