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2 years ago

Please help with math, will give brainliest

Mathematics

2 answers:

tino4ka555 [31]2 years ago

3 0

Answer:

1; 31.2 2; 12.4 3; 30.8 4; 118.4 5; 16.53 (i ran out of time or else i wouldve finished, just use google for answers! ^_^)

done the rest, just Step-by-step explanation:

soldier1979 [14.2K]2 years ago

3 0

1.31
2.12
3.30
4.118
5.16
6.74
7.20
8.98

9.341

10.377

You might be interested in

If 30 gallons of water weighs 249 pounds, what is the weight of 7 gallons of water in pounds?

gizmo_the_mogwai [7]

Answer: 58.1 pounds

Step-by-step explanation:

Use proportion to solve peroblem.

30:249=7:x

30x=249*7

x=249*7/30

x=58.1 pounds

6 0

2 years ago

The mean number of words per minute (WPM) read by sixth graders is 8888 with a standard deviation of 1414 WPM. If 137137 sixth g

Bingel [31]

Noticing that there is a pattern of repetition in the question (the numbers are repeated twice), we are assuming that the mean number of words per minute is 88, the standard deviation is of 14 WPM, as well as the number of sixth graders is 137, and that there is a need to estimate the probability that the sample mean would be greater than 89.87.

Answer:

"The probability that the sample mean would be greater than 89.87 WPM" is about $\\ P(z>1.56) = 0.0594$ .

Step-by-step explanation:

This is a problem of the distribution of sample means. Roughly speaking, we have the probability distribution of samples obtained from the same population. Each sample mean is an estimation of the population mean, and we know that this distribution behaves normally for samples sizes equal or greater than 30 $\\ n \geq 30$ . Mathematically

$\\ \overline{X} \sim N(\mu, \frac{\sigma}{\sqrt{n}})$ [1]

In words, the latter distribution has a mean that equals the population mean, and a standard deviation that also equals the population standard deviation divided by the square root of the sample size.

Moreover, we know that the variable Z follows a normal standard distribution, i.e., a normal distribution that has a population mean $\\ \mu = 0$ and a population standard deviation $\\ \sigma = 1$ .

$\\ Z = \frac{\overline{X} - \mu}{\frac{\sigma}{\sqrt{n}}}$ [2]

From the question, we know that

The population mean is $\\ \mu = 88$ WPM
The population standard deviation is $\\ \sigma = 14$ WPM

We also know the size of the sample for this case: $\\ n = 137$ sixth graders.

We need to estimate the probability that a sample mean being greater than $\\ \overline{X} = 89.87$ WPM in the distribution of sample means. We can use the formula [2] to find this question.

The probability that the sample mean would be greater than 89.87 WPM

$\\ Z = \frac{\overline{X} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$\\ Z = \frac{89.87 - 88}{\frac{14}{\sqrt{137}}}$

$\\ Z = \frac{1.87}{\frac{14}{\sqrt{137}}}$

$\\ Z = 1.5634 \approx 1.56$

This is a standardized value and it tells us that the sample with mean 89.87 is 1.56 standard deviations above the mean of the sampling distribution.

We can consult the probability of P(z<1.56) in any cumulative standard normal table available in Statistics books or on the Internet. Of course, this probability is the same that $\\ P(\overline{X} < 89.87)$ . Then

$\\ P(z$

However, we are looking for P(z>1.56), which is the complement probability of the previous probability. Therefore

$\\ P(z>1.56) = 1 - P(z$

$\\ P(z>1.56) = P(\overline{X}>89.87) = 0.0594$

Thus, "The probability that the sample mean would be greater than 89.87 WPM" is about $\\ P(z>1.56) = 0.0594$ .

5 0

2 years ago

Solve for ,×. Then, circle whether each angle pair is complementary or supplementary.

Svet_ta [14]

See the solution above..☝☝

HOPE THIS WILL HELP!!!

<h3>PLZZ PLZZ MARK ME BRAINLIEST!!</h3>

6 0

2 years ago

A micro-photograph of a human hair shows the hair magnified 150 times. If the hair is

stepan [7]

Answer:

The actual width of the hair is 20 / 150 = 0.13 mm

Step-by-step explanation:

Scaling

Objects can be represented in a reduced or augmented size by using scaling which is basically multiplying or dividing by a constant factor. We use scaling in several applications of real-life.

The human hair is magnified 150 times by a micro-phtograph. This is the scale factor.

The hair can be seen 2 cm wide in the photograph.

Converting to millimeters, 2 cm = 2*10 = 20 millimeters.

The actual width of the hair is 20 / 150 = 0.13 mm

6 0

2 years ago

An entrepreneur sold a damaged bedspread for $130.50, thereby making a loss of 13% on the cost price. Determine the cost price o

Anit [1.1K]

Answer:

$1003.84615

Step-by-step explanation:

130.5 = x * 0.13

130.5/0.13 = x

x = 1003.84615

4 0

2 years ago