. HELP DUE IN A FEW MIN ASAP im stupidssssss

The sampling distribution of the proportion follows the normal distribution when the values np and nq are greater than or equal

Keith_Richards [23]

I dont know. So i am sorry ask someone alse. Thanks

8 0

4 years ago

The heights of North American women are normally distributed with a mean of 64 inches and a standard deviation of 2inches.a. Wha

Charra [1.4K]

Answer:

a) $P(X>66)=P(Z>1)=1-P(Z$

b) $P(\bar X >66)=P(Z>2)=1-P(Z$

c) $P(\bar X >66)=P(Z>10)=1-P(Z$

Step-by-step explanation:

1) 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".

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".

2) Part a

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

$X \sim N(64,2)$

Where $\mu=64$ and $\sigma=2$

We are interested on this probability

$P(X>66)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>66)=P(\frac{X-\mu}{\sigma}>\frac{66-\mu}{\sigma})=P(Z>\frac{66-64}{2})=P(Z>1)$

And we can find this probability on this way:

$P(Z>1)=1-P(Z$

3) Part b

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

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

$P(\bar X >66)=P(Z>\frac{66-64}{\frac{2}{\sqrt{4}}}=2)$

And using a calculator, excel or the normal standard table we have that:

$P(Z>2)=1-P(Z$

4) Part c

$P(\bar X >66)=P(Z>\frac{66-64}{\frac{2}{\sqrt{100}}}=10)$

And using a calculator, excel or the normal standard table we have that:

$P(Z>10)=1-P(Z$

3 0

3 years ago

Please help! this is a geometry question.

Phantasy [73]

Answer:

C

Step-by-step explanation:

The ratio is 1:4 so 1 of the object equals 4 of the scale drawing

30*4=120^2 cm

4 0

3 years ago

One year after you buy a tree, it is 10 feet tall. Each year after you buy the tree, it grows 2 feet. Write a function that repr

Drupady [299]

Answer:

10 years

Step-by-step explanation:

We are told that One year after you buy a tree, it is 10 feet tall. Thus, it's initial height after 1 year is 10 ft.

Now we are told that each year after you buy the tree, it grows 2 feet. This means that it's height after you bought it was; f(0) = 10 - 2 = 8ft

Thus,

f(1) = 8 + 2 = 10

f(2) = 8 + 2 + 2 = 12

f(3) = 8 + 2 + 2 + 2 = 14

The pattern here is;

f(x) = 8 + 2x

Where x is number of years

Thus, for it to reach a maximum height of 28 ft;

28 = 8 + 2x

Subtract 8 from both sides to give;

28 - 8 = 2x

2x = 20

x = 20/2

x = 10 years

4 0

3 years ago

Write the equation of the line that passes through the points (8,-2)(8,−2) and (5,5)(5,5). Put your answer in fully reduced poin

VladimirAG [237]

Answer:

The the equation of the line through the points (8, -2) and (5, 5) in slope-intercept form is

$y=-\frac{7}{3} x+\frac{50}{3}$

Step-by-step explanation:

Let's start by calculation the slope of the line by finding the slope of the segment that joins the two given points (8, -2) and (5, 5):

$slope=\frac{y_2-y_1}{x_2-x_1} \\slope=\frac{5-(-2)}{5-8}\\slope=\frac{7}{-3} \\slope=-\frac{7}{3}$

Now we use this slope in the general slope-intercept form of a line;

$y=mx+b\\y=-\frac{7}{3} x+b$

and then we calculate the value of the intercept "b" by using one of the given points through which the line must pass (for example (5,5) ), and solving for b:

$y=-\frac{7}{3} x+b\\5=-\frac{7}{3} (5)+b\\5=-\frac{35}{3} +b\\b=5+\frac{35}{3}\\b=\frac{50}{3}$

The the equation of the line is

$y=-\frac{7}{3} x+\frac{50}{3}$

5 0

4 years ago