What is the answer to (5x20)-6

Which of the following is an appropriate estimate of the distance, in miles, from the west coast to the east coast of the United

vlada-n [284]

D

10^-3 would make a decimal, so would 10^-1.
10^1 would be 30 miles, 10^3 would be 3 with 3 zeros ( 3000 miles) which would be most accurate

5 0

3 years ago

. name four rays shown?

Aliun [14]

The rays shown in the pictur: Ray VX, YZ , XY, ZV..... Plus more!

4 0

3 years ago

I need some serious help rn, i got stuck

nordsb [41]

Answer:

I think it is add 11 both sides? If it is wrong i am sooooo sorry

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

3x-10-4

snow_lady [41]

Answer/Step-by-step Explanation:

1. 3x - 10 +4 if x = 3

To evaluate, plug in the value of x in the expression given

3(3) - 10 + 4 = 9 - 10 + 4

= 3

2. $\frac{x}{2} + 6x$

if x = -12

$\frac{(-12)}{2} + 6(-12)$

- 6 - 72 = - 78

3. 8(x - y), if x = 2, y = 6

8(2 - 6) = 8(-4) = -32

4. x + xy, if x = 3, y = -2.5

3 + (3)(-2.5) = 3 + (-7.5)

= 3 - 7.5 = - 4.5

5. (2x)² + 6, if x = -2

(2*-2)² + 6 = (-4)² + 6

= 16 + 6 = 22

6. 3x + 4y - 3x, if x = 2, y = 4

3(2) + 4(4) - 3(2) = 6 + 16 - 6

= 16

7. $-10x + \frac{4}{x}$

If x = -2

$-10(-2) + \frac{4}{-2}$

20 + (-2) = 20 - 2 = 18

8. 3(8x - 10) + 5x, if x = ½

3(8*½ - 10) + 5(½)

3(4 - 10) + 2.5

3(-6) + 2.5 = -18+2.5 = - 20.5 or 20½

9. x + 8y - (x)², if x = -5, y = ¼

-5 + 8(¼) - (-5)² = -5 + 2 - (25)

= -3 - 25 = -28

10. (8x)² + 6x + 2, if x = -3

(8*-3)² + 6(-3) + 2 = (-24)² - 18 + 2

= 576 - 18 + 2 = 560

11. 2x² + 4y² + xy, if x = ½, y = 2

2(½)² + 4(2)² + (½)(2)

= 2(¼) + 4(4) + 1

= ½ + 16 + 1 = ½ + 17 = 17½

12. 8x + 2y, if x = 1.5, y = -2.2

8(1.5) + 2(-2.2)

12 - 4.4 = 7.6

13. $\frac{5}{2}(x - 6) + 4$

if x = 8.

$\frac{5}{2}(8 - 6) + 4$

$\frac{5}{2}(2) + 4$

= 5 + 4 = 9

14. 3x - 8x² + 7, if x = 4.5

3(4.5) - 8(4.5)² + 7

13.5 - 8(20.25) + 7

13.5 - 162 + 7 = -141.5

15. -2x² + 8y, if x = 3, y = -9

-2(3)² + 8(-9)

-2(9) - 72 = - 18 - 72 = 90

16. (-5x)² - 3x + x, if x = -3.5

(-5*-3.5)² - 3(-3.5) +(-3.5)

(17.5)² + 10.5 - 3.5

306.25 + 10.5 - 3.5 = 313.25

8 0

3 years ago

A news report states that the 99% confidence interval for the mean number of daily calories consumed by participants in a medica

expeople1 [14]

Answer:

The sample mean is of 1925 calories.

The margin of error is of 75 calories.

The sample standard deviation is of 109.7992 calories.

Step-by-step explanation:

Sample mean:

The sample mean is the mean value of the two bounds of the confidence interval. So

$M = \frac{1850 + 2000}{2} = 1925$

The sample mean is of 1925 calories.

The margin of error

Difference between the bounds and the sample mean. So

2000 - 1925 = 1925 - 1850 = 75 calories.

The margin of error is of 75 calories.

Sample standard deviation:

Here, I am going to expand on the t-distribution.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 18 - 1 = 17

99% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.99}{2} = 0.995$ . So we have T = 2.898

The margin of error is:

$M = T\frac{s}{\sqrt{n}}$

In which s is the standard deviation of the sample and n is the size of the sample.

Since $M = 75, T = 2.898, n = 18$

$M = T\frac{s}{\sqrt{n}}$

$75 = 2.898\frac{s}{\sqrt{18}}$

$s = \frac{75\sqrt{18}}{2.898}$

$s = 109.7992$

The sample standard deviation is of 109.7992 calories.

6 0

3 years ago