If a sector of a circle has a radius of 15m and an arc length of 25 meters, find the central

Michmoo Computer Company sells computers and computer parts by mail. The company assures its customers that products are mailed

Anastaziya [24]

Answer: (60.858, 69.142)

Step-by-step explanation:

The formula to find the confidence interval for mean :

$\overline{x}\pm z_c\dfrac{\sigma}{\sqrt{n}}$ , where $\overline{x}$ is the sample mean , $\sigma$ is the population standard deviation , n is the sample size and $z_c$ is the two-tailed test value for z.

Let x represents the time taken to mail products for all orders received at the office of this company.

As per given , we have

Confidence level : 95%

n= 62

sample mean : $\overline{x}=65$ hours

Population standard deviation : $\sigma=18$ hours

z-value for 93% confidence interval: $z_c=1.8119$ [using z-value table]

Now, 93% confidence the mean time taken to mail products for all orders received at the office of this company :-

$65\pm (1.8119)\dfrac{18}{\sqrt{62}}\\\\ 65\pm4.142\\\\=(65-4.142,\ 65+4.142)\\\\= (60.858,\ 69.142)$

Thus , 93% confidence the mean time taken to mail products for all orders received at the office of this company : (60.858, 69.142)

8 0

4 years ago

At a Psychology final exam, the scores are normally distributed with a mean 73 points and a standard deviation of 10.6 points. T

USPshnik [31]

Answer:

The score that separates the lower 5% of the class from the rest of the class is 55.6.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

$\mu = 73, \sigma = 10.6$

Find the score that separates the lower 5% of the class from the rest of the class.

This score is the 5th percentile, which is X when Z has a pvalue of 0.05. So it is X when Z = -1.645.

$Z = \frac{X - \mu}{\sigma}$

$-1.645 = \frac{X - 73}{10.6}$

$X - 73 = -1.645*10.6$

$X = 55.6$

The score that separates the lower 5% of the class from the rest of the class is 55.6.

3 0

3 years ago

Solve the equation 4x^2 + 24x + 13 = 2x^2+ 6x to the nearest tenth.

Licemer1 [7]

Answer:

-0.8 and -8.2

Step-by-step explanation:

To solve a quadratic you first need to have one side of the equation equal to zero (because x-intercepts are when y is zero).

4x^2 + 24x + 13 = 2x^2 + 6x

2x^2 + 18x + 13 = 0

Then you can use the quadratic formula to solve for x. You will then come to

-18 ± sqrt(220) / 4

This will simplify out (rounding to the nearest tenth) to -0.8 and -8.2

6 0

3 years ago

The diameter of the moon is about 3500 km. Approximate the surface area of the moon using the formula for the surface area of a

horrorfan [7]

Answer:

$3.8465 *10^7$ square kilometers

Step-by-step explanation:

The surface area of a sphere can be found using the formula $SA=4\pi r^2$ . Since the diameter is 3500 km then its radius is half of this. 3500 divided in two is 1,750 units. Substitute r=1,750.

$SA=4\pi r^2\\SA = 4 \pi (1750)^2\\SA = 4 \pi *3,062,500\\SA =38,465,000$

The surface area of the moon is about 38,465,000 square kilometers. Write this is scientific notation using base. $3.8465 *10^7$

5 0

3 years ago

Find the GCF of 28c-12

stira [4]

THE GCF IS 4; I hope this helps

5 0

3 years ago

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