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1 year ago

Katarina bought a package of 500 stickers. Each sheet in the package has 20 stickers.

1 answer:

5 0

I think there are 125 heart stickers and 375 star stickers. 20/4 = 5, so there are 5 heart stickers per sheet. there are 25 sheets in the package, 5 x 25 = 125. if the remaining stickers on a sheet are stars then there are 15 star stickers per sheet. 15 x 25 = 375.

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the population at Saint Maria High increased from 1800 students ten years ago to 1926 students last year. What was the percent i

Ket [755]

It’s a 7% increase. When you want to find percent increase/decrease, you want to subtract the numbers of the before and after. In this case, subtract 1926 and 1800, which will equal 126. Then, percent over 100 would be the first fraction, but since you don’t know the percent, put x. The second fraction is the amount of change over the original number. In this case, the amount of change will be 126 and the original is 1800. x/100=126/1800 now you just cross multiply and solve. You will end up with 7

3 0

1 year ago

Read 2 more answers

At a recent county fair, you observed that at one stand people's weight was forecasted, and were surprised by the accuracy (with

MatroZZZ [7]

Answer:

a)Slope: $\hat \beta_1 =\frac{7625.9}{1248.9}=6.106$

Intercept: $\hat \beta_o = 157.955 -6.106 (69.686)=-267.548$

b) $r=\frac{7625.9}{\sqrt{[1248.9][94228.8]}}=0.657$

And the determination coeffecient is $r^2 = 0.657^2 =0.432$

Step-by-step explanation:

Data given and definitions

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"

When we conduct a multiple regression we want to know about the relationship between several independent or predictor variables and a dependent or criterion variable.

n=110, $\sum x_i y_i = \sum (X-\bar X)(Y-\bar Y) =7625.9,\sum x^2_i=\sum (x-\bar x)^2 =1248.9 , sum y^2_i=\sum(y-\bar y)^2 =94228.8$

$\sum Y_i =17375 , \sum X_i = 7665.5$

Part a

The slope is given by this formula:

$\hat \beta_1 =\frac{\sum (x-\bar x) (y-\bar y)}{\sum (x-\bar x )^2}$

If we replace we got:

$\hat \beta_1 =\frac{7625.9}{1248.9}=6.106$

We can find the intercept with the following formula

$\hat \beta_o = \bar y -\hat \beta_1 \bar x$

We can find the average for x and y like this:

$\bar X=7665.5/110 =69.686, \bar y= 17375/110=157.955$

And replacing we got:

$\hat \beta_o = 157.955 -6.106 (69.686)=-267.548$

Part b

In order to calculate the correlation coefficient we can use this formula:

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

For our case we have this:

n=110, $\sum x_i y_i = \sum (X-\bar X)(Y-\bar Y) =7625.9,\sum x^2_i=\sum (x-\bar x)^2 =1248.9 , sum y^2_i=\sum(y-\bar y)^2 =94228.8$

So we can find the correlation coefficient replacing like this:

$r=\frac{7625.9}{\sqrt{[1248.9][94228.8]}}=0.657$

And the determination coeffecient is $r^2 = 0.657^2 =0.432$

6 0

2 years ago

Imagine we wanted to investigate whether the reason for quitting smoking affects success rate. We recruited a sample of 120 smok

Paha777 [63]

Answer:

I think is C

Step-by-step explanation:

8 0

1 year ago

During the 2005 football season, Team Tackle beat Team Sack by 3 points. If their combined scores totaled 15, find the individ

Verizon [17]

Answer:

Team tackle scored 9 points.

Team Sack scored 6 points.

Step-by-step explanation:

9+6=15 and 9 is three more than 6.

7 0

1 year ago

Read 2 more answers

The ratio of the lengths of the sides of △ABC is 3:6:7. M, N, and K are the midpoints of the sides. Perimeter of △MNK equals 7.4

artcher [175]

Answer:

AB=2.775

BC=5.55

CA=6.475

Step-by-step explanation:

Since midpoints split their sides in half, we can see that the triangle MNK formed by the midpoints will be half the perimeter of the triangle ABC. Since P of MNK = 7.4, we know that the perimeter of ABC = 7.4 * 2, which is 14.8. Now we can split the 14.8 so that it follows the ratio.

3+6+7=16

14.8/16=0.925

AB=0.925*3=2.775

BC=0.925*6=5.55

CA=0.925*7=6.475

8 0

2 years ago