A normal population has a mean of 60 and a standard deviation of 12. You select a random sample of 9. Compute the probability the sample mean is : (a). Greater than 63. (b). Less than 56. (c). Between 56 and 63.

Answers

Answer 1

Using the normal distribution and the central limit theorem, it is found that there is a:

a) 0.2266 = 22.66% probability that the sample mean is greater than 63.

b) 0.1587 = 15.87% probability that the sample mean is less than 56.

c) 0.6147 = 61.47% probability that the sample mean is between 56 and 63.

In a normal distribution 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]

It 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, which is the percentile of X.By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

In this problem:

Mean of 60, thus [tex]\mu = 60[/tex].Standard deviation of 12, thus [tex]\sigma = 12[/tex].Sample size of 9, thus [tex]n = 9, s = \frac{12}{\sqrt{9}} = 4[/tex].

Item a:

This probability is 1 subtracted by the p-value of Z when X = 63, so:

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

By the Central Limit Theorem

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

[tex]Z = \frac{63 - 60}{4}[/tex]

[tex]Z = 0.75[/tex]

[tex]Z = 0.75[/tex] has a p-value of 0.7734.

1 - 0.7734 = 0.2266

0.2266 = 22.66% probability that the sample mean is greater than 63.

Item b:

This probability is the p-value of Z when X = 56, so:

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

[tex]Z = \frac{56 - 60}{4}[/tex]

[tex]Z = -1[/tex]

[tex]Z = -1[/tex] has a p-value of 0.1587.

0.1587 = 15.87% probability that the sample mean is less than 56.

Item c:

This probability is the p-value of Z when X = 63 subtracted by the p-value of Z when X = 56.

These p-values were found in the previous items, so:

0.7734 - 0.1587 = 0.6147

0.6147 = 61.47% probability that the sample mean is between 56 and 63.

A similar problem is given at https://brainly.com/question/24663213


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Answers

9514 1404 393

Answer:

  y = 0x + 15

Step-by-step explanation:

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Writing the slope explicitly, the equation is ...

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Simplified, the equation is

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Question 7
Maya, Tom, and Greg sent a total of 153 text messages over their cell phones during the weekend, Greg sent 9 fewer messages than Maya,
Tom sent 4 times as many messages as Greg, How many messages did they each send?

Answers

[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]

The messages sent by them are ~

Maya = 33 messages

Greg = 24 messages

Tom = 96 messages

[tex] \large \boxed{ \mathfrak{Step\:\: By\:\:Step\:\:Explanation}}[/tex]

Let the number of messages sent by Maya be x,

messages sent by Greg = x - 9

messages sent by Tom = 4(x - 9)

and, total number of messages sent by them all together is equal to ~ 153

that is ~

[tex]x + x - 9 + 4(x - 9) = 153[/tex]

[tex]2x - 9 + 4x - 36 = 153[/tex]

[tex]6x - 45 = 153[/tex]

[tex]6x = 153 + 45[/tex]

[tex]6x = 198[/tex]

[tex]x = 198 \div 6[/tex]

[tex]x = 3 3[/tex]

Hence, the messages sent by them are ~

Maya = x = 33

Greg = x - 9 = 33 - 9 = 24

Tom = 4(x - 9) = 4 × 24 = 96

Let Maya send m

Greg send m-9

Tom sent 4(m-9)

ATQ

m+m-9+4(m-9)=1532m-9+4m-36=1536m-45=1536m=153+456m=198m=33

Greg=33-9=24

Tom=4(24)=96

Can you help me plz.

Answers

Answer:

Step-by-step explanation:

pls gimme brainliest if im correct

Answer:

7.77, 7[tex]\frac{4}{9}[/tex], 7.4, 7[tex]\frac{3}{4}[/tex]

Step-by-step explanation:

convert the fractions to decimals

[tex]\frac{4}{9}[/tex] = .44 so 7.44

[tex]\frac{3}{4}[/tex] = .25 so 7.25

7.77, 7.44, 7.40, 7.25

they look to already be in order.

have a lovely day <3

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Answer:

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Step-by-step explanation:

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Step-by-step explanation:

Answer:

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Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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What is Algebra?

Algebra is the study of abstract symbols, while logic is the manipulation of all those ideas.

The acronym PEMDAS stands for Parenthesis, Exponent, Multiplication, Division, Addition, and Subtraction. This approach is used to answer the problem correctly and completely.

Given;

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=(4/5)/(2/3)

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Therefore, by algebra answer in simplest form will be 6/5.

More about the Algebra link is given below.

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Answers

Answer:

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Step-by-step explanation:

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Hope this helps! :)

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Step-by-step explanation:

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Step-by-step explanation:

okokokokokipullup

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Step-by-step explanation:

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b

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

Tim asked his classmates if they preferred rock music or pop music. The ratio of students who liked pop music to rock music was 3 to 4. If Tim asked 14 classmates, how many like pop music?

Answers

Answer:

10.5 people like pop music.

Step-by-step explanation:

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Answer:

BIN

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Absolute Maximum:
f(-3):
Absolute minimum:
Range:
Domain:
Is the graph a function?:
Relative Maximum(s):
Increasing Interval(s):
Decreasing Interval(s):
Relative minimum(s):​

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Answers

Answers:

Absolute maximum:  4f(-3) = -2Absolute minimum: Does not existRange: [tex](-\infty, 4][/tex]Domain:  [tex][-4, \infty)[/tex]Is it a function? YesRelative Maximum(s): 2Increasing Interval(s): [tex](-2, 1)[/tex] ... interval notationDecreasing Interval(s): [tex](-\infty, -2) \ \cup \ (1, \infty)[/tex]Relative Minimum(s):  -4

=====================================================

Explanations:

The absolute maximum occurs at the highest point. Specifically, it's the largest y output possible. In this case, it's y = 4.

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

To determine the value of f(-3), we draw a vertical line through -3 on the x axis. Mark where this vertical line crosses the curve. Let's say its point P. From point P, draw a horizontal line until you reach the y axis. You should arrive at y = -2. Therefore, f(-3) = -2.

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

The absolute min is similar to the absolute max, but now we're looking at the lowest y output possible. No such y value exists because the curve goes on forever downward.

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

The range is the set of all possible y outputs. The range in compound inequality notation is [tex]-\infty < y \le 4[/tex] indicating y can be anything between negative infinity and 4. We can include 4. The range in interval notation is [tex](-\infty, 4][/tex]. Note the use of the square bracket so that we include the 4.

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

The domain is the set of x inputs possible. The smallest such input allowed is x = -4. There is no largest input because the graph goes on forever to the right. The domain is any x value such that [tex]-4 \le x < \infty[/tex] which condenses to the interval notation [tex][-4, \infty)[/tex]

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

This is a function because we cannot draw a single vertical line through more than one point on this curve; hence, this graph passes the vertical line test.

Put another way, any x input in the domain leads to exactly one and only one y output. This is a nonvisual way to prove we have a function.

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

A relative maximum occurs at any peak or mountain region. It is relatively the highest point in the neighborhood/region of points. There's one such mountain peak and it's at (1,2). We can think of this as a vertex of sorts for an upside down parabola. So the relative max is y = 2 because we're only concerned with the y value.

Note: y = 4 is not a relative max because there aren't any points to the left of that endpoint. A relative extrema must have points to the left and right of it for it to be a valid neighborhood.

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

Imagine this curve represents a roller coaster. As we move to the right, going uphill on this curve is an increasing section. That would be the interval from x = -2 to x = 1. So we'd say -2 < x < 1 which condenses to the interval notation (-2, 1). This is not to be confused with ordered pair (x,y) notation.

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

Now we consider when we move downhill when we move to the right. This occurs on the intervals [tex]-\infty < x < -2[/tex] and also [tex]1 < x < \infty[/tex]. We don't include any of the endpoints. This is because at x = -2 and x = 1, the cart is neither moving uphill nor downhill. These locations are stationary resting points so to speak.

Those two inequalities mentioned convert to the interval notations [tex](-\infty, -2)[/tex] and [tex](1, \infty)[/tex] in that order.

Once we determined those separated disjoint regions, we glue them together with the use of the union symbol U.

Our answer for this part would be [tex](-\infty, -2) \ \cup \ (1, \infty)[/tex]. Any point in this collective region will be moving downhill when moving left to right.

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

This is similar to a relative maximum, but this time we're looking at the lowest valley point of a certain neighborhood. This is at (-2,-4). Therefore, the relative min is y = -4.

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Answers

Answer:

7 means ones because it is the units

Step-by-step explanation:

4= thousand

5= hundred

6= tens

7=ones / unit

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Five times the sum of a number and 9 equals 4

Answers

Answer:

I think it might be (x + 9)5 = 4 or 5(x + 9) = 4. I'm not really sure.

I hoped this helped

Have a nice day!

Step-by-step explanation:

2
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WIN
(x - 4) = 2x. (1 point)
O
o

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Answer:

D. X=-2

Step-by-step explanation:

The two figures are similar. Find the ratios (red to blue) of the perimeters and of the areas. Write the ratios as fractions in simplest form.

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i need a picture or something man

Step-by-step explanation:

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B

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Answers

Answer:

27/7

Step-by-step explanation:

by calculator..

or you can do these steps

1/4(4t-9)=1/8(t+9) "divided l.h.s and r.h.s by ⅛"

2(4t-9)=t+9.

8t-18=t+9

7t=27

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2. ĐỊNH THỨC
2.1. Giải phương trình:
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Answer:

Step-by-step explanation:

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