Calculate the sample variance and sample standard deviation for the following frequency distribution of heights in centimeters for a sample of 8-year-old boys. If necessary, round to one more decimal place than the largest number of decimal places given in the data. Heights in Centimeters Class Frequency 116.1 - 120.0 38 120.1 - 124.0 24 124.1 - 128.0 28 128.1 - 132.0 43 132.1 - 136.0 29

Answers

Answer 1

Answer:

[tex]s^2 = 0.9938[/tex] --- sample variance

[tex]s = 0.9969[/tex] --- sample standard deviation

Step-by-step explanation:

Given

[tex]\begin{array}{cc}{Heights} & {Frequency} & {116.1-120.0} & {38} & {120.1-124.0} & {24} &{124.1-128.0} & {28} & {128.1-132.0} & {43} & {132.1-136.0} & {29} \ \end{array}[/tex]

Required

Calculate the sample variance and sample standard deviation

First, we calculate the midpoint of each class:

[tex]\begin{array}{ccc}{Heights} & {Frequency} & {m} &{116.1-120.0} & {38} & {118.05}& {120.1-124.0} & {24}& {122.05} &{124.1-128.0} & {28} &{126.05}& {128.1-132.0} & {43} & {130.05} &{132.1-136.0} & {29} &{134.05}\ \end{array}[/tex]

The midpoints are calculated by taking the average of the class intervals.

For instance:

Class 116.1 to 120.0 has a midpoint of

[tex]m = \frac{1}{2}(116.1+120.0)[/tex]

[tex]m = \frac{1}{2}(236.1)[/tex]

[tex]m = 118.05[/tex]

The same approach is applied to other classes.

Next, is to calculate the mean:

[tex]\bar x = \frac{\sum fx}{\sum f}[/tex]

In this case, it is:

[tex]\bar x = \frac{\sum fm}{\sum f}[/tex]

Where

[tex]m = midpoint[/tex]

So, we have:

[tex]\bar x = \frac{118.05*38+122.05*24+126.05*28+130.05*43+134.05*29}{38+24+28+43+29}[/tex]

[tex]\bar x = \frac{20424.10}{162}[/tex]

[tex]\bar x = 126.07[/tex]

The sample variance (s^2) is:

[tex]s^2 = \frac{\sum(m - \bar x)^2}{\sum f -1}[/tex]

This gives:

[tex]s^2 = \frac{(118.05-126.07)^2+(122.05-126.07)^2+(126.05-126.07)^2+(130.05-126.07)^2+(134.05-126.07)^2}{38+24+28+43+29-1}[/tex]

[tex]s^2 = \frac{160.002}{161}[/tex]

[tex]s^2 = 0.9938[/tex]

The sample standard deviation (s) is:

[tex]s = \sqrt{s^2[/tex]

[tex]s = \sqrt{0.9938[/tex]

[tex]s = 0.9969[/tex]


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Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

Answer:

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Step-by-step explanation:

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Answers

Answer:

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Answers

Answer:

Step-by-step explanation:

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Step-by-step explanation:

The perpendicular line has a negative reciprocal slope.

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Answers

Step-by-step explanation:

Using Pythagoras theorem

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Answers

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Step-by-step explanation:

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Answers

Answer:

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The cube root of a number is the factor that we multiply by itself three times to get that number.

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Answer:

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Answers

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Answers

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Answers

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Step-by-step explanation:

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Answer:

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Answers

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Answers

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Step-by-step explanation:

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Answers

Answer:

No

Step-by-step explanation:

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19 students × 2 cookies = 38 cookies is what you need

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7 packages × 6 cookies = 42 cookies

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Answers

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Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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