The world record for the 100 m sprint is 9.77 seconds How long would it take to run 1 m at the speed

A 42-inch board is to be cut into three pieces so that the second piece is twice as long as the first piece and the third piece

Karo-lina-s [1.5K]

Answer: 7 inches

Step-by-step explanation:

If x is the first piece, and the second piece is twice as long, then the second piece is 2x.

If the third piece is three times as long as the first piece, x, then the third piece is 3x.

The 42-inch board must be equal to all 3 pieces, so we will set up an equation and solve for x.

42 = x + 2x + 3x

42 = 6x

7 = x

The first piece is 7 inches long.

Learn more about your question here: brainly.com/question/20320071

5 0

1 year ago

The proprietor of a boutique in New York wanted to determine the average age of his customers. A random sample of 25 customers r

jolli1 [7]

Answer:

$28-2.064\frac{10}{\sqrt{25}}=23.872$

$28+2.064\frac{10}{\sqrt{25}}=32.128$

So on this case the 95% confidence interval would be given by (23.9;32.1)

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".

$\bar X=28$ represent the sample mean

$\mu$ population mean (variable of interest)

s=10 represent the sample standard deviation

n=25 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=25-1=24$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,24)".And we see that $t_{\alpha/2}=2.064$

Now we have everything in order to replace into formula (1):

$28-2.064\frac{10}{\sqrt{25}}=23.872$

$28+2.064\frac{10}{\sqrt{25}}=32.128$

So on this case the 95% confidence interval would be given by (23.9;32.1)

7 0

3 years ago

Answer the following.

nexus9112 [7]

Step-by-step explanation:

1075 students were asked how close they live to the college. The table shows the results below with some values missing. Enter the correct values in the boxes remembering to use the % symbol where necessary.

20 to 25: given 20%

20% of 1,075 = 215

15 to 19: given 12%

12% of 1,075 = 129

10 to 14: given 516 students

(516/1,075)*100 = 48%

5 to 9: given 162 students

(162/1,075)*100 = 15.07%

< 5: given 53 students

(53/1,075)*100 = 4.93%

3 0

10 months ago

GIVING BRANLIEST

ivann1987 [24]

Complementary and adjacent

7 0

3 years ago

The graph represents the number of cups of flour for the number of cups of sugar ina cake recipe. Which ratio is accurate based

Dmitry_Shevchenko [17]

7.5
I’m not sure
Sorry

7 0

2 years ago

Read 2 more answers