Can someone help me out

Answer:

0.9922 = 99.22% probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The production manager claims they have a mean life of 83 months with a variance of 81.

This means that [tex]\mu = 83, \sigma = \sqrt{81} = 9[/tex]

Sample of 146:

This means that [tex]n = 146, s = \frac{9}{\sqrt{146}}[/tex]

What is the probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors?

This is 1 subtracted by the p-value of Z when X = 81.2. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{81.2 - 83}{\frac{9}{\sqrt{146}}}[/tex]

[tex]Z = -2.42[/tex]

[tex]Z = -2.42[/tex] has a p-value of 0.0078.

1 - 0.0078 = 0.9922.

0.9922 = 99.22% probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors.

Answer:

D.

Step-by-step explanation:

The required inequality is given as x ≥ 100 as the water boils at 100°C and above, Option B is correct.

Inequality can be defined as the relation of the equation containing the symbol of ( ≤, ≥, <, >) instead of the equal sign in an equation.

here,
As given in the question,
Water boils at 100°C and above,
So let x be the temperature of the water,
And according to the condition,
x ≥ 100° C

Thus, the inequality x ≥ 100 is shown in option B.

Thus, the required inequality is given as x ≥ 100 as the water boils at 100°C and above, and Option B is correct.

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Answer:

B

Step-by-step explanation:

5³.5^×

simply means

5³×5^×

using indices rule,

multiplication is addition

5 is common

so 5(³+×)

hence 5^3+×

Answer:

There isn't sufficient evidence that support the claim that mean cost differs from $117.91

Step-by-step explanation:

Given that :

Population Mean cost, μ = 117.91

Sample size, n = 36

Sample mean, xbar = 122.57

Sample standard deviation, s = 20

The hypothesis :

H0 : μ = 117.91

H0 : μ ≠ 117.91

Using the one sample t test :

Test statistic

(xbar - μ) ÷ s/sqrt(n)

T = (122.57 - 117.91) ÷ 20/sqrt(36)

T = 4.66 / 3.333

T = 1.398

Decision region :

Reject H0 ; If Pvalue < α

α = 0.10

Degree of freedom, df = n - 1 = 36 - 1 = 35

Pvalue(1.398, 35) = 0.1709

Since 0.1709 > 0.10 ; WE fail to reject H0 ; therefore there isn't sufficient evidence that support the claim that mean cost differs from $117.91

z -5 =4

neutralize the left -5 by adding 5 on both sides

z -5 (+5) = 4 (+5)

z = 9

Correct option is "multiplying a fraction by a repeating decimal."

Explanation:

Since multiplying a fraction is a rational and repeating decimal is also rational, therefore, it's result is also rational.

Hope it helps you... pls mark brainliest if it helped you

Answer:

17.3

Step-by-step explanation:

14.4 x 1.2

= 17.28

= 17.3 ( approximately )

Answer:

8 ten dollar bills

20 fifty dollar bills

Step-by-step explanation:

x = number of 10 dollar bills

y = number of 50 dollar bills

x+y = 28

10x+50y = 1080

Multiply the first equation by -10

-10x -10y = -280

Add this to the second equation

-10x -10y = -280

10x+50y = 1080

-----------------------

 40y = 800

Divide by 40

40y/40 = 800/40

y = 20

Now find x

x+y =28

x+20 = 28

x = 28-20

x= 8

Answer:

0.0079 = 0.79% probability that she randomly plants the trees so that all 5 sycamores are next to each other and all 5 palm trees are next to each other.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The trees are arranged, so, to find the number of outcomes, the arrangements formula is used.

Arrangements formula:

The number of possible arrangements of n elements is given by:

[tex]A_n = n![/tex]

Desired outcomes:

5 sycamores(5! possible ways) and then the 5 palm trees(5! possible ways)

5 palm trees(5! possible ways) then the 5 sycamores(5! possible ways).

[tex]D = 2*5!*5![/tex]

Total outcomes:

Arrangements of 10 plants, so:

[tex]T = 10![/tex]

What is the probability that she randomly plants the trees so that all 5 sycamores are next to each other and all 5 palm trees are next to each other?

[tex]p = \frac{D}{T} = \frac{2*5!*5!}{10!} = 0.0079[/tex]

0.0079 = 0.79% probability that she randomly plants the trees so that all 5 sycamores are next to each other and all 5 palm trees are next to each other.

Answer:

18. 84 ft² or 18.85 ft² when rounded to the nearest tenth

Step-by-step explanation:

2πrh+2πr²

2× 3.14 × 1 × 2= 12.56

2 × 3.14 × 1² = 6.28

12.56 + 6.28 = 18.84

Have a great day :)

Answer:

18.85 [tex]ft^2\\[/tex]

*You should run the numbers yourself as well. Sometimes different calculators will get marginally different numbers or use a different rounding for [tex]\pi[/tex] that gives a slightly different answer*

Step-by-step explanation:

Surface area of a cylinder: [tex]2\pi rh+2\pi r^2[/tex]

Where h is the height and r is the radius. Remember that the radius is half the diameter, and the diameter is a straight line that passes through a circle.

I could be wrong, but I think you had the correct equation but used the diameter in stead of the radius to get 50.36.

Radius: 1   Height: 2

Plug numbers into equation:

[tex]A=2\pi (1)(2)+2\pi (1)^2= 18.8495. . .[/tex]

I hope that helps!

Step-by-step explanation:

A=140sq. units

Step-by-step explanation:

ABCD

A=13

B=15

C=14

D=20

C=14×14

=196sqr.units

Answer:

9 hours

Step-by-step explanation:

12 people take 15 hours to complete one job. First let's ask how long it would take 18 people working at the same rate to complete the same job? We can use proportions to answer this

[tex]\frac{12 people}{15 hours} = \frac{18 people}{x hours}\\x = \frac{18\times15}{12} = 22.5[/tex]

Now we know that one job takes 18 people 22.5 hours, so 2/5 of the job would take

[tex]\frac{18\times15}{12} \times \frac{2}{5} = 9[/tex]

Step-by-step explanation:

hope it will help u

hope it will help u please mark me as brillient...

Answer:

939 is the answer

Step-by-step explanation:

plz Mark me as the brainlist

Differentiating both sides of

xy = 99

with respect to t yields

x dy/dt + y dx/dt = 0

When x = 11, we have

11y = 99   ==>   y = 9

and we're given that dy/dt = -4 at this point, which means

11 (-4) + 9 dx/dt = 0   ==>   dx/dt = 44/9

NA = A + W

By adding one unit to length, we increase the overall area by the width of the rectangle. This is because the formula for the area of a rectangle is A = l x w. So, NA = (l + 1) x w = (l x w) + w = A + w.

Answer: D

"Separating the students on the list into boys and girls and choosing a sample from each group that is proportional to the size of the group."

Step-by-step explanation:

You are sampling an equal amount of boys and girls since your getting an equal sample of each gender. (Not random)

The option that is not a random sample is:

Separating the students on the list into boys and girls and choosing a sample from each group that is proportional to the size of the group.

Option D is the correct answer.

It is the way of choosing a number of required items from a population given.

Each item has an equal probability of being chosen.

We have,

We will see which option is a sample that is not random.

A. Going through the list and choosing the first 25 names on the list.

Going through the list means every name has an equal chance of getting chosen.

This is a random sample.

B. Writing each student’s name on a card and then drawing out 25 names without looking.

Since we are drawing out 25 names without looking, all the students' names have an equal chance of getting drawn.

This is a random sample.

C. Choosing one student at random from the list and going through the list and choosing every fifth student until she has 25 names.

Choosing one student at random means every student has an equal chance of getting chosen.

This is a random sampling.

D. Separating the students on the list into boys and girls and choosing a sample from each group that is proportional to the size of the group.

The students are separated into boys and girls and the sample is chosen from each group so we are selecting the sample from the separated group.

This can not be a random sampling.

Thus,

The option that is not a random sample is:

Separating the students on the list into boys and girls and choosing a sample from each group that is proportional to the size of the group.

Option D is the correct answer.

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Answers:

First bottle's unit cost = 27 cents per oz

Second bottle's unit cost = 27 cents per oz

Both have the same unit cost.

----------------------------------------

Work Shown:

unit cost = price/(number of ounces)

1st bottle unit cost = (1.35)/(5) = 0.27 dollars per oz = 27 cents per oz

2nd bottle unit cost = (2.16)/(8) = 0.27 dollars per oz = 27 cents per oz

Both lead to the same unit cost. Therefore, you can pick either option and it doesn't matter.

9514 1404 393

Answer:

  undefined

Step-by-step explanation:

A rational expression is undefined when its denominator is zero.

Answer

nghiệmTrảingu       từng bước:

Answer:

0.8997 = 89.97% probability of a bulb lasting for at most 622 hours.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

Mean of 590 hours, standard deviation of 25 hours.

This means that [tex]\mu = 590, \sigma = 25[/tex]

Find the probability of a bulb lasting for at most 622 hours.

This is the p-value of Z when X = 622.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{622 - 590}{25}[/tex]

[tex]Z = 1.28[/tex]

[tex]Z = 1.28[/tex] has a p-value of 0.8997.

0.8997 = 89.97% probability of a bulb lasting for at most 622 hours.

Answer:

A) children attended=98 b) students attended=60 c)adults attended=49

Step-by-step explanation:

system%28a%2Bc%2Bx=207%2Cc%2Fa=2%2C5c%2B7x%2B12a=1498%29

Simplify and solve the system.

-

a%2B2a%2Bx=207

3a%2Bx=207

x=207-3aandc=2a

-

The revenue equation can be written in terms of just one variable, a.

10a%2B7%28207-3a%29%2B12a=1498

Solve for a;

use it to find x and c.

FURTHER STEPS

-

10a%2B1449-21a%2B12a=1498

a%2B1449=1498

a=98-49

highlight%28a=49 -------adults

-

c=2a

c=2%2A49

highlight%28c=98 -------children

-

x=207-a-c

x=207-49-98

highlight%28x=60 ---------students

Answer:

The mean number of the students who develop hypertension over a life time is 7.8.

Step-by-step explanation:

For each person, there are only two possible outcomes, either they will develop hypertension, or they will not. The probability of a person developing hypertension is independent of any other person, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

Probability of exactly x successes on n repeated trials, with p probability.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

Suppose that the probability that a person will develop hypertension over a life time is 60%.

This means that [tex]p = 0.6[/tex]

13 graduating students from the same college are selected at random.

This means that [tex]n = 13[/tex]

Find the mean number of the students who develop hypertension over a life time

[tex]E(X) = np = 13*0.6 = 7.8[/tex]

The mean number of the students who develop hypertension over a life time is 7.8.

Answer:

36 is the answer

Step-by-step explanation:

Answer:

36

Step-by-step explanation:

72: 2×2×2×3×3

108: 2×2×3×3×3

180: 2×2×3×3×5

here, common factors are 2,2,3 and 3 ..

so.. HCF: 2×2×3×3

•°•HCF=36 ..

Answer:

(123)(62)=x

Step 1: Simplify both sides of the equation.

7626=x  

Step-by-step explanation:

Have a good day.

Answer:7,626

Step-by-step explanation:The easiest way I do it is by taking the numbers and putting them under each other like this

123

 62

then take the number 2 for example and multiply it by 3 then 20 then 100 and do the same with the 6=60 and heres how I solve it

2 x 3=6      2 x 20=40     2 x 100=200       60 x 3=180     60 x 20=1,200    60 x 100=6,000 now take all the numbers and add them

6+40+200=246

180+1,200+6,000=7,380

7,380+246=7,626

(if this helps in anyway feel free to put brainiest but thats your choice) :) happy to help.

9514 1404 393

Answer:

  A = 108.78°

  a = 11 mi

  b = 7 mi

Step-by-step explanation:

The sum of angles in a triangle is 180°, so the third angle is ...

  A = 180° -38.71° -32.51°

  A = 108.78°

__

The remaining sides can be found from the law of sines.

  a/sin(A) = c/sin(C)

  a = sin(A)·c/sin(C) ≈ 0.946762 × 11.163896

  a ≈ 11 mi

  b = sin(B)·11.163896 ≈ 0.625379 × 11.163896

  b ≈ 7 mi

Answer: -2(d) is the answer.

Step-by-step explanation:

x1 = 3

y1 = -5

x2 = -2

y2 = 5

slope (m) = rise/run = (y2 - y1)/(x2-x1)

                                =(5-(-5))/(-2-3)

                                 =   10/-5

                                 = -2

Answer:

  (3t -7)²

Step-by-step explanation:

We know that the square of a binomial is ...

  (a -b)² = a² -2ab +b²

So, when we see the first and last terms are both perfect squares, we suspect that the trinomial is a perfect square trinomial.

  9t² = (3t)²

  49 = 7²

  -42t = -2(3t)(7) . . . . confirming we have a perfect square

The factorization is ...

  (3t -7)²

Step-by-step explanation:

area=length×width

2.4=x×1.2

1.2x=2.4

x=2.4÷1.2

x=2

therefore width = 2cm

The length of the rectangle is 2 meters.

We have,

Width of rectangle= 1.2m

Area of rectangle = 2.4 m²

To find the length of a rectangle when given its width and area, you can use the formula:

Length = Area / Width

So, the length rectangle

Length = 2.4 m² / 1.2 m

Length = 2 meters

Therefore, the length of the rectangle is 2 meters.

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Answer:

Step-by-step explanation:

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