Which function will start at the y-axis at (0,7) 1. y=7x 2. y=x+7 3. y=x-7 4. y=x+5

Consider a parent population with mean 75 and a standard deviation 7. The population doesn’t appear to have extreme skewness or

Aleks04 [339]

Answer:

a) $\bar X \sim N(\mu=375, \sigma={\bar X}=\frac{7}{\sqrt{40}}=1.107)$

b) Since the sample size is large enough n>30 and the original distribution for the random variable X doesn’t appear to have extreme skewness or outliers, the distribution for the sample mean would be bell shaped and symmetrical.

c) $P(\bar X \leq 77)=P(Z$

d) See figure attached

Step-by-step explanation:

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 central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

Let X the random variable of interest. We know from the problem that the distribution for the random variable X is given by:

$E(X) = 75$

$sd(X) = 7$

We take a sample of n=40 . That represent the sample size

Part a

From the central limit theorem we know that the distribution for the sample mean $\bar X$ is also normal and is given by:

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

$\bar X \sim N(\mu=375, \sigma={\bar X}=\frac{7}{\sqrt{40}}=1.107)$

Part b

Since the sample size is large enough n>30 and the original distribution for the random variable X doesn’t appear to have extreme skewness or outliers, the distribution for the sample mean would be bell shaped and symmetrical.

Part c

In order to answer this question we can use the z score in order to find the probabilities, the formula given by:

$z=\frac{\bar X- \mu}{\frac{\sigma}{\sqrt{n}}}$

And we want to find this probability:

$P(\bar X \leq 77)=P(Z$

We can us the following excel code: "=NORM.DIST(1.807,0,1,TRUE)"

Part d

See the figure attached.

8 0

3 years ago

Find the value of 5.8 ÷ 1.2.

EastWind [94]

Your answer is 4.83

5 0

3 years ago

On a certain hot summer's day, 391 people used the public swimming pool. The daily prices are $1.25 for children and $2.25 for

Tomtit [17]

127 children and 264 adults swam at the public pool that day

Step-by-step explanation:

On a certain hot summer's day

391 people used the public swimming pool
The daily prices are $1.25 for children and $2.25 for adults
The receipts for admission totaled $752.75

We need to find how many children and how many adults swam at the public pool that day

Assume that the number of children is x and the number of adult is y in that day

∵ x children swam that day

∵ y adults swam that day

∵ 391 people used the swimming pool that day

- Add x and y, then equate the sum by 391

∴ x + y = 391 ⇒ (1)

∵ The daily price for children is $1.25 per child

∵ The daily price for an adult is $2.25

∵ The receipts for admission totaled $752.75

- Multiply x by 1.25 and y by 2.25, then add the products and

equate the sum by 752.75

∴ 1.25x + 2.25y = 752.75

- Divide each term by 1.25 to simplify the equation

∴ x + 1.8y = 602.2 ⇒ (2)

Now we have a system of equations to solve it

Subtract equation (1) from equation (2) to eliminate x

∵ (x - x) + (1.8y - y) = 602.2 - 391

∴ 0.8y = 211.2

- Divide both sides by 0.8

∴ y = 264

- Substitute the value of y in equation (1) to find x

∵ x + 264 = 391

- Subtract 264 from both sides

∴ x = 127

127 children and 264 adults swam at the public pool that day

Learn more:

You can learn more about the system of equations in brainly.com/question/2115716

#LearnwithBrainly

6 0

3 years ago

-2w - 5w it wont let me submit it as=is so i am typing random things.

Fofino [41]

The answer would be -7w

8 0

3 years ago

What is the slope of the line with equation y=12x

fomenos

When you have an equation of the form y = mx + b (which you do in this case), the slope is always equal to the coefficient of x, which is m or 12 in this case. Since there is no "b" in your equation, you could say that b=0, and the line is known to cross the y axis at zero.

In case you are interested, if the equation said y = 12 x + 3 the slope of the line would still be 12 but the line would cross the y axis at 3. If the equation said y = 12x -4, the line would have a slope of 12 and would cross the y axis at -4.

5 0

3 years ago

Which function will start at the y-axis at (0,7)1. y=7x2. y=x+73. y=x-74. y=x+5​

Which function will start at the y-axis at (0,7)1. y=7x2. y=x+73. y=x-74. y=x+5