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Ahat [919]
3 years ago
7

Could anybody help with this confused ?!!

Mathematics
1 answer:
ss7ja [257]3 years ago
3 0
X=4 y=9

4 [times] 4-9=7
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2. MNM Corporation gives each of its employees an aptitude test. The scores on the test are normally distributed with a mean of
antiseptic1488 [7]

Answer:

a) Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:

X \sim N(75,15)  

Where \mu=75 and \sigma=25

The distribution for the sample mean \bar X is given by:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

b) \mu represent the true average for the scores of the aptitude test

c) We can calculate the z scores and we got:

z = \frac{70.14-75}{\frac{15}{\sqrt{25}}}= -1.62

z = \frac{82.14-75}{\frac{15}{\sqrt{25}}}= 2.38

And we can calculate the probability with this difference:

P(-1.62

d) We can calculate the z scores and we got:

z = \frac{82.68-75}{\frac{15}{\sqrt{25}}}= 2.56

And we can calculate the probability with this difference:

P(Z

e) We can calculate the z scores and we got:

z = \frac{78.69-75}{\frac{15}{\sqrt{25}}}= 1.23

And we can calculate the probability with this difference:

P(Z

Step-by-step explanation:

a. What are the expected value, the standard deviation, and the shape of the sampling distribution of \bar X?

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:

X \sim N(75,15)  

Where \mu=75 and \sigma=25

The distribution for the sample mean \bar X is given by:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

b. What is the random variable in this problem? Define it in words.

\mu represent the true average for the scores of the aptitude test

c. What is the probability that the average aptitude test score in the sample will be between 70.14 and 82.14?

We can calculate the z scores and we got:

z = \frac{70.14-75}{\frac{15}{\sqrt{25}}}= -1.62

z = \frac{82.14-75}{\frac{15}{\sqrt{25}}}= 2.38

And we can calculate the probability with this difference:

P(-1.62

d. What is the probability that the average aptitude test score in the sample will be greater than 82.68?

We can calculate the z scores and we got:

z = \frac{82.68-75}{\frac{15}{\sqrt{25}}}= 2.56

And we can calculate the probability with this difference:

P(Z

e. What is the probability that the average aptitude test score in the sample will be less than 78.69?

We can calculate the z scores and we got:

z = \frac{78.69-75}{\frac{15}{\sqrt{25}}}= 1.23

And we can calculate the probability with this difference:

P(Z

7 0
3 years ago
Can anyone please help me <br> Factor. 3n4+21n3+27n2 Enter your answer in the box.
Valentin [98]
<span>i got --> x= (0, -1)   </span>
7 0
4 years ago
Read 2 more answers
What multiplys to be 1 but adds up to be 4
balandron [24]

Answer: 3 & 1


Step-by-step explanation:


6 0
4 years ago
Mrs Grey is buying decorative ribbon of three different colors: blue, silver, and yellow. Blue ribbon is sold in rolls of 15 met
olganol [36]

Answer:

4 rolls of blue ribbon,

5 rolls of silver ribbon,

3 rolls of yellow ribbon.

Step-by-step explanation:

We have been given that Mrs Grey is buying decorative ribbon of three different colors: blue, silver, and yellow. Blue ribbon is sold in rolls of 15 meters, silver is sold in rolls of 12 meters, and yellow comes in rolls of 20 meters.

As Mrs. Grey needs to have same length of each ribbon, so we will find the least common multiple of 15, 12 and 20.

Multiples of 15 are: 15, 30, 45, 60, 75, 90,...

Multiples of 12 are: 12, 24, 36, 48, 60, 72, 84,...

Multiples of 20 are: 20, 40, 60, 80,100,...

We can see that 60 is the least common multiple of 15, 12 and 20.

\text{The smallest number of rolls of blue ribbon}=\frac{60}{15}=4

Therefore, Mrs. Grey should buy 4 rolls of blue ribbon.

\text{The smallest number of rolls of silver ribbon}=\frac{60}{12}=5

Therefore, Mrs. Grey should buy 5 rolls of silver ribbon.

\text{The smallest number of rolls of yellow ribbon}=\frac{60}{20}=3

Therefore, Mrs. Grey should buy 3 rolls of yellow ribbon.

3 0
4 years ago
Yesterday 6 of the 20 students in ms.healys. class took the bus to school
Rus_ich [418]
If 6/20 took the bus then there is 14/20 remaining.
6/20 simplified is 3/10.
14/20 simplified is 7/10.

Hope This Helps You!
<span>Good Luck Studying :)</span>
8 0
3 years ago
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