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3 years ago

Write a real world problem that can be solved by the equation y+8=20

2 answers:

6 0

Phil started with 20 cookies and now there are 8 how many cookies did phil eat?
20-8=12 so phil ate 12 out of 20 cookies

Oduvanchick [21]3 years ago

6 0

Cary and Mary have 15 cupcakes.Mary has 9 cupcakes.How many cupcakes does Cary have?
y+9=15

Subtract 9 from both sides.

y = 6

Cary has 6 cupcakes

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Which point is a solution to y>-3x +6? a. (0,6) b. (1,-2) C. (1,2) d. (4,5)

Klio2033 [76]

Answer:

actually i dont know either im trying to find that out

Step-by-step explanation:

i dont get it

8 0

2 years ago

(1 point) Suppose we want a 95% confidence interval for the average amount spent on books by freshmen in their first year at col

Ne4ueva [31]

Answer:

a) $n=(\frac{1.960(16)}{5})^2 =39.33 \approx 40$

So the answer for this case would be n=40 rounded up to the nearest integer

b) For this case if we see the formula for the margin of error

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (a)

We can see that the margin of error is inversely proportional to the sample size so if we want a samller margin of error we need a LARGER sample

Answer: LARGER

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean

$\sigma=16$ represent the population standard deviation

n represent the sample size

Solution to the problem

Part a

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (a)

And on this case we have that ME =5 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

$n=(\frac{1.960(16)}{5})^2 =39.33 \approx 40$

So the answer for this case would be n=40 rounded up to the nearest integer

Part b

For this case if we see the formula for the margin of error

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (a)

We can see that the margin of error is inversely proportional to the sample size so if we want a samller margin of error we need a LARGER sample

Answer: LARGER

5 0

3 years ago

Sally gave her brother $3.95 in quarters and dimes. if the number of quarters is 6 more than the number of dimes, how many quart

WARRIOR [948]

13 quarters
q=6+d
25q+10d=395
solve for q and get 13

7 0

3 years ago

Read 2 more answers

Solve systems of equations by algebraically x-2y=7 2x+5y =5

Natali [406]

Answer:

(5,-1) or x=5 y=-1

Step-by-step explanation:

I used the substitution method to solve this!

1. Pick one of your equations and solve for one of the variables. I chose the first equation and solved for x.

x-2y=7

(Move the -2y to the other side of the equation in order to get the x by itself. You do the opposite, so it becomes +2y.)

x=2y+7

2. Now take your second equation and plug in what you got for x into the x variable.

2(2y+7)+5y=5

(Multiple 2 by everything inside of the parentheses.)

4y+14+5y=5

(We want to get the y by itself, so move the 14 to the other side.)

4y+5y=-14+5

(Combine all the like terms.)

9y=-9

(Divide the 9 from the y. What you do to one side you must do to the other.)

y=-1

3. Since you have one variable solved for. Now take the first equation and plug in your y.

x-2(-1)=7

(Multiple -2 by -1)

x+2=7

(Move the 2 to the other side in order to get the x by itself.)

x=5

4. If needed, plug in your x and y values into the equations in order to check your answer.

Hope this could help!

8 0

3 years ago

Read 2 more answers

You can buy 3 pounds of strawberries for 3.99 at Kroger knowing this what is the unit rate per pound of strawberries and how muc

Varvara68 [4.7K]

Answer:

1.33 per pound
6.65 for 5 pounds

Step-by-step explanation:

To find cost per pound, divide cost by pounds.

3.99/(3 lb) = 1.33/lb . . . . cost per pound

The cost of 5 pounds will be found by multiplying that by 5:

(1.33/lb)(5 lb) = 6.65 . . . cost of 5 pounds

7 0

2 years ago