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3 years ago

Assume the random variable X is normally distributed with mean μ=50 and standard deviation σ=7. Find the 81st percentile.

Mathematics

1 answer:

Ahat [919]3 years ago

4 0

Answer:

$P(81)=56.16$

Step-by-step explanation:

From the question we are told that:

Mean $\mu=50$

Standard Deviation $\sigma=7$

Percentile 81st

Generally Probability of 81st Percentile

$P(Z$

Using Standard normal Table

$P(Z$

Therefore the 81st percentile is given as

$P(81)=z*\sigma *\mu$

$P(81)=0.88*7*50$

$P(81)=56.16$

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Before tax, and miscellaneous charges, Jason's cell phone bill is $100 per month plus $0.15 for every text message that he sends

cestrela7 [59]

Answer:

Step-by-step explanation:

100 dollars month

100

plus

100+

0.15 per text

100+15t

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3 years ago

Elijah brought a total of 16 pounds of peanuts and cashew nuts and paid $49.50 if peanuts cost $2.75 per pound and cashews nuts

maria [59]

Answer:

The number of pounds of cashew is 11

Step-by-step explanation:

Let P represent the peanut

Let C represent the cashew nut.

From question, we were told that Elijah brought a total of 16 pounds of peanuts and cashew nuts. This can be written as:

P + C = 16 (1)

The total cost = $49.50

Cost per peanut = $2.75

Cost per cashew = $3.25

The above can be represented as:

49.50 = 2.75P + 3.25C. (2)

From equation 1,

P + C = 16

P = 16 — C

Substitute the value of P into equation 2:

49.50 = 2.75P + 3.25C.

49.50 = 2.75(16 — C) + 3.25C

49.50 = 44 — 2.75C + 3.25C

49.50 = 44 + 0.5C

Collect like terms

49.50 — 44 = 0.5C

5.5 = 0.5C

Divide both side by 0.5

C = 5.5/0.5

C = 11

Therefore, the number of pounds of cashew is 11

8 0

3 years ago

Which equation has the same solutions as the equation given below?

Lapatulllka [165]

Answer:

Step-by-step explanation:

Also solved eveything

(x+9)^2=49

x^2+18x+81=49

x^2+18x+32=0

a=1, b=18 and c=32

x= (-18 +/- Sqrt (18^2-4×32))/2

x= (-18 +/- Sqrt (324-128))/2

x= (-18 +/- Sqrt (196))/2

x= (-18 +/- 14)/2

x= (-18 +14)/2 = -4/2 =-2

x= (-18 -14)/2 = -32/2 =-16

3 0

3 years ago

Read 2 more answers

5.65 times 3.4 estimate

lidiya [134]

We can round 5.65 up to 6 and 3.4 down to 3.
3 * 6 = 18
now let's see how close our estimate is to the real answer
5.65 * 3.4 = 19.21
Our answer was pretty close to the real answer!

Hope I helped!
~ Zoe

3 0

3 years ago

Read 2 more answers

The weekly salaries of sociologists in the United States are normally distributed and have a known population standard deviation

netineya [11]

THIS IS THE COMPLETE QUESTION BELOW;

The weekly salaries of sociologists in the United States are normally distributed and have a known population standard deviation of 425 dollars and an unknown population mean. A random sample of 22 sociologists is taken and gives a sample mean of 1520 dollars.

Find the margin of error for the confidence interval for the population mean with a 98% confidence level.

z0.10 z0.05 z0.025 z0.01 z0.005

1.282 1.645 1.960 2.326 2.576

You may use a calculator or the common z values above. Round the final answer to two decimal places.

Answer

Margin error =210.8

Given:

standard deviation of 425

sample mean x=1520 dollars.

random sample n= 22

From the question We need to to calculate the margin of error for the confidence interval for the population mean .

CHECK THE ATTACHMENT FOR DETAILED EXPLANATION

4 0

3 years ago