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2 years ago

Please help due ASAP Show workings

Mathematics

1 answer:

Luba_88 [7]2 years ago

3 0

Answer:

CD=66

Step-by-step explanation:

12x-30=6x+18

6x=48

x=8

12(8)-30=66

CD=66

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The sports shop has 9 part-time employees and 21 full-time employees. What percentage of the employees at the sports shop work p

eduard

Answer:

30% of employees work part-time

Step-by-step explanation:

i just added 9 and 21 which is 30 and then i figured out that 9 is 30% of 30

7 0

2 years ago

An automobile dealer wants to see if there is a relationship between monthly sales and the interest rate. A random sample of 4 m

SVETLANKA909090 [29]

Answer:

a) $y=-6.254 x +75.064$

b) r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

Step-by-step explanation:

Assuming the following dataset:

Monthly Sales (Y) Interest Rate (X)

22 9.2

20 7.6

10 10.4

45 5.3

Part a

And we want a linear model on this way y=mx+b, where m represent the slope and b the intercept. In order to find the slope we have this formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=278.65-\frac{32.5^2}{4}=14.5875$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=696.9-\frac{32.5*97}{4}=-91.225$

And the slope would be:

$m=\frac{-91.225}{14.5875}=-6.254$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{32.5}{4}=8.125$

$\bar y= \frac{\sum y_i}{n}=\frac{97}{4}=24.25$

And we can find the intercept using this:

$b=\bar y -m \bar x=24.25-(-6.254*8.125)=75.064$

So the line would be given by:

$y=-6.254 x +75.064$

Part b

For this case we need to calculate the correlation coefficient given by:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

$r=\frac{4(696.9)-(32.5)(97)}{\sqrt{[4(278.65) -(32.5)^2][4(3009) -(97)^2]}}=-0.937$

So then the correlation coefficient would be r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

6 0

3 years ago

Convert 6 yards into meters. Round your answer to the nearest tenth.

Helga [31]

Answer:

5.4864

Step-by-step explanation:

to the nearest tenth probably 0.5

6 0

2 years ago

the volume of a cylindrical watering can is 100cm^3. If the radius is doubled, then how much water can the new can hold?

9966 [12]

V=(pi)(2r^2)(h)
V=4(pi)(r^2)(h)
V=4(100 aka the old volume)
V=400cm^3

4 0

3 years ago

A box contains $7.05 in nickels, dimes, and quarters. There are 42 coins in all, and the sum of the numbers of nickels and dimes

german

I BELIEVE that there are 22 quarters, 13 dimes, and 7 nickels I’m super super sorry if wrong

3 0

2 years ago