X an y are proportional. What is the missing value in the table <br>

What 2 numbers add up to get -1 and multiply to get -20

Dovator [93]

The two numbers that add up to get -1 and multiply to get -20 are -5 and 4
-5*4=-20
-5+4=-1
I hope this helps

3 0

3 years ago

Calculate the sample standard deviation and sample variance for the following frequency distribution of hourly wages for a sampl

lidiya [134]

Answer:

(a) The sample variance is 16.51

(a) The sample standard deviation is 4.06

Step-by-step explanation:

Given

$\begin{array}{cc}{Class} & {Frequency} & 8.26 - 10.00 & 20 &10.01-11.75 & 38 &11.76 - 13.50& 36 & 13.51-15.25 &25&15.26-17.00 &27 &\ \end{array}$

Solving (a); The sample variance.

First, calculate the class midpoints.

This is the mean of the intervals.

i.e.

$x_1 = \frac{8.26+10.00}{2} = \frac{18.26}{2} = 9.13$

$x_2 = \frac{10.01+11.75}{2} = \frac{21.76}{2} = 10.88$

$x_3 = \frac{11.76+13.50}{2} = \frac{25.26}{2} = 12.63$

$x_4 = \frac{13.51+15.25}{2} = \frac{28.76}{2} = 14.38$

$x_5 = \frac{15.26+17.00}{2} = \frac{32.26}{2} = 16.13$

So, the table becomes:

$\begin{array}{ccc}{Class} & {Frequency} & {x} & 8.26 - 10.00 & 20&9.13 &10.01-11.75 & 38 &10.88&11.76 - 13.50& 36 &12.63& 13.51-15.25 &25&14.38&15.26-17.00 &27 &16.13\ \end{array}$

Next, calculate the mean

$\bar x = \frac{\sum fx}{\sum f}$

$\bar x = \frac{20*9.13 + 38 * 10.88+36*12.63+25*14.38+27*16.13}{20+38+36+25+27}$

$\bar x = \frac{1845.73}{146}$

$\bar x = 12.64$

Next, the sample variance is:

$\sigma^2 = \frac{\sum f(x - \bar x)^2}{\sum f - 1}$

So, we have:

$\sigma^2 = \frac{20*(9.13-12.63)^2 + 38 * (10.88-12.63)^2 +...........+27 * (16.13 -12.63)^2}{20+38+36+25+27-1}$

$\sigma^2 = \frac{2393.6875}{145}$

$\sigma^2 = 16.51$

The sample standard deviation is:

$\sigma = \sqrt{\sigma^2}$

$\sigma = \sqrt{16.51}$

$\sigma = 4.06$

6 0

2 years ago

The volume of a cone is 108 pi cubic inches. Its height is 4 inches. What is the radius of the cone? Round answer to nearest ten

leonid [27]

$\bf \textit{volume of a cone}\\\\ V=\cfrac{\pi r^2 h}{3}~~ \begin{cases} r=radius\\ h=height\\ -----\\ V=108\pi \\ h=4 \end{cases}\implies 108\pi =\cfrac{\pi r^2(4)}{3}\implies 324\pi =4\pi r^2 \\\\\\ \cfrac{324\pi }{4\pi }=r^2\implies 81=r^2\implies \sqrt{81}=r\implies 9=r$

7 0

3 years ago

Read 2 more answers

Make a number that has a 6 that is 10 times the value of the digit 6 in 165,438 Comparing digits in whole numbers

Ipatiy [6.2K]

Answer:

An example of such number is 1,645,378 ( The value of 6 here is 600,000)

Step-by-step explanation:

Here, we want to compare digits in whole

numbers.

The value of 6 in 165,438 = 60,000

Now, we want a number that is 10 times the value of 6 here

10 times the value of 6 here will be 10 * 60,000 = 600,000

So we want a number which has the value of 6 in it as 600,000

The number in this case as an example can be ;

1,645,378

3 0

3 years ago

Find the number of ways 4 members from a family of 5 can line up for a photo shoot?

Ira Lisetskai [31]

They can line up 20 different ways

6 0

3 years ago

X an y are proportional. What is the missing value in the table ​

X an y are proportional. What is the missing value in the table