Find the distance between the points (2,10) and (-6,-7)

What process do you use to find the percent change of a quantity?

Olenka [21]

Find the amount of change by subtracting the two quantities. Divide this number by the original (starting) quantity, and convert to percent form by moving the decimal 2 places to the right.

4 0

3 years ago

A random sample of 20 items is selected from a population. When computing a confidence interval for the population mean, what nu

kumpel [21]

Answer:

For this case since the sample size is lower than 30 , n =20<30, is not appropiate use the normal standard distribution to calculate the confidence interval for the mean, and then for this case is better use the t distribution since takes in count the correction factor to approximate the distribution of the true parameter.

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

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

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

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

For this case since the sample size is lower than 30 , n =20<30, is not appropiate use the normal standard distribution to calculate the confidence interval for the mean, and then for this case is better use the t distribution since takes in count the correction factor to approximate the distribution of the true parameter.

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

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

8 0

4 years ago

Solve for p. P=? 12 = p 11 12

Mariulka [41]

Answer:

p = 144/11

Step-by-step explanation:

12/11 = p/12

~Simplify

12/11 = 1/12p

~Multiply 12 to both sides

144/11 = p

Best of Luck!

8 0

3 years ago

Fifty specimens of a new computer chip were tested for speed in a certain application, along with 50 specimens of chips with the

Murljashka [212]

Answer:

Under 99% confidence level we can say that mean speed of the new chips is greater than that of the old chips

Step-by-step explanation:

$H_{0}$ : Mean speed of the new chip is the same as the old chip

$H_{a}$ : Mean speed of the new chip is greater than the old chip

to calculate the z-statistic we can use the formula:

z= $\frac{M_{n}-M_{o}}{\sqrt{\frac{s_{n}^2}{N_{n}} +\frac{s_{o}^2}{N_{o}} } }$

if we put the numbers then

z= $\frac{495.6-481.2}{\sqrt{\frac{19.4^2}{65}} +\frac{14.3^2}{65} } }$ =4.8171

The probability of this z-statistic is < 0.001 Therefore Under 99% confidence level we can say that mean speed of the new chips is greater than that of the old chips

4 0

3 years ago

In circle pp, ad¯¯¯¯¯ad¯ is a diameter and bc¯¯¯¯¯bc¯ is perpendicular to ad¯¯¯¯¯ad¯ at ee. if pd=7pd=7 and ae=4ae=4, find cece.

kvv77 [185]

See the attached figure.

ad is a diameter of the circle with center p

∵ pd = radius = 7 ⇒⇒⇒ ∴ ad = 2 * radius = 2 * 7 = 14
∵ ae = 4 ⇒⇒⇒ ∴ ed = ad - ae = 14 - 4 = 10
∵ ad is a diameter
Δ acd is a triangle drawn in a half circle
∴ Δ acd is a right triangle at c
∵ bc ⊥ ad at point e
By applying euclid's theorem inside Δ acd
∴ ce² = ae * ed
∴ ce² = 4 * 10 = 40
∴ ce = √40 = 2√10 ≈ 6.325

3 0

4 years ago