Which expression is equivalent to 5(4x + 5)

In the kite shown, m

VARVARA [1.3K]

Where is the rest of the problem?

7 0

2 years ago

Solve the system of equations below. A. B. C. D.

timofeeve [1]

Answer:

A. (-7 -2)

Step-by-step explanation:

You can eliminate y by multiplying the first equation by 7 and subtracting 6 times the second equation:

7(-3x +6y) -6(5x +7y) = 7(9) -6(-49)

-21x +42y -30x -42y = 63 +294 . . . . eliminate parentheses

-51x = 357 . . . . . . . . collect terms

x = -7 . . . . . . . divide by -51. This matches answer choice A.

7 0

2 years ago

In a simple random sample of 14001400 young people, 9090% had earned a high school diploma. Complete parts a through d below.

ratelena [41]

Answer:

(a) The standard error is 0.0080.

(b) The margin of error is 1.6%.

(c) The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d) The percentage of young people who earn high school diplomas has increased.

Step-by-step explanation:

Let p = proportion of young people who had earned a high school diploma.

A sample of n = 1400 young people are selected.

The sample proportion of young people who had earned a high school diploma is:

$\hat p=0.90$

(a)

The standard error for the estimate of the percentage of all young people who earned a high school diploma is given by:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

Compute the standard error value as follows:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

$=\sqrt{\frac{0.90(1-0.90)}{1400}}\\$

$=0.008$

Thus, the standard error for the estimate of the percentage of all young people who earned a high school diploma is 0.0080.

(b)

The margin of error for (1 - α)% confidence interval for population proportion is:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

Compute the critical value of z for 95% confidence level as follows:

$z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96$

Compute the margin of error as follows:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

$=1.96\times 0.0080\\=0.01568\\\approx1.6\%$

Thus, the margin of error is 1.6%.

(c)

Compute the 95% confidence interval for population proportion as follows:

$CI=\hat p\pm MOE\\=0.90\pm 0.016\\=(0.884, 0.916)\\\approx (88.4\%,\ 91.6\%)$

Thus, the 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d)

To test whether the percentage of young people who earn high school diplomas has increased, the hypothesis is defined as:

H₀: The percentage of young people who earn high school diplomas has not increased, i.e. p = 0.80.

Hₐ: The percentage of young people who earn high school diplomas has not increased, i.e. p > 0.80.

Decision rule:

If the 95% confidence interval for proportions consists the null value, i.e. 0.80, then the null hypothesis will not be rejected and vice-versa.

The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

The confidence interval does not consist the null value of p, i.e. 0.80.

Thus, the null hypothesis is rejected.

Hence, it can be concluded that the percentage of young people who earn high school diplomas has increased.

8 0

3 years ago

Is b - 12 = - 5; 17 solution

Pani-rosa [81]

No the answer to the solution would be 7

7 0

3 years ago

A proportional relationship between the number of pounds of cabbage (x) and the price in dollars (y) is graphed, and the ordered

Marta_Voda [28]

Answer: A. 1 pound of cabbage will cost 40 cents. B. (10,4) means that 10 pounds of cabbage will cost 4 dollars.

Step-by-step explanation:

If it is proportional that means the y value divided by the x value will give you a constant slope.

So using that use the coordinates (5,2) to find the cost of 1 pound of cabbage.

2/5 = 0.4

so you could write the equation y= 0.4x where x is the number of pound.

Part A: y= 0.4(1)

y= $0.40 which means one pound of cabbage will cost 40 cents.

Part B. (10,4) in this case it will means that for 10 pounds of cabbage it will cost $4.

Plot it into the equation and find out

in the coordinates (10,4) 4 is the y and 10 is the x

4= 0.4(10)

4= 4

Which means it true that 10 pounds of cabbage will cost 4 dollars.

5 0

3 years ago