Area of circle 6mm(radius) in terms of pi

IgorLugansk [536]

Using the normal distribution, the probability that a worker selected at random makes between $500 and $550 is: 2.15%.

<h3>Normal Probability Distribution</h3>

The z-score of a measure X of a normally distributed variable with mean mu and standard deviation sigma is given by:

Z = (X - mu)/sigma

The z-score measures how many standard deviations the measure is above or below the mean.

Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.

The mean and the standard deviation are given as follows:

mu = 400, sigma = 50

The probability is the <u>p-value of Z when X = 550 subtracted by the p-value of Z when X = 500</u>, hence:

X = 550:

Z = (X - mu)/sigma

Z = (550 - 400)/50

Z = 3

Z = 3 has a p-value of 0.9987.

X = 500:

Z = (X - mu)/sigma

Z = (500 - 400)/50

Z = 2

Z = 2 has a p-value of 0.9772.

0.9987 - 0.9772 = 0.0215 = 2.15% probability.

More can be learned about the normal distribution at brainly.com/question/15181104

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6 0

2 years ago

Need points ?Answer question simple.

Tresset [83]

Answer:

45 degrees

Step-by-step explanation:

A straight line is an angle with a measure of 180°, but becasue it looks like we have two angles that create the 180° angle, therefore, it is a supplementary angle.

Knowing this

2X = 90° (right angle)

so (2X) + (2X) = 180° (supplementary angle)

Therefore, to find X you can do

2X = 90

divide by 2 on both sides (to isolate the variable we are trying to find which is X)

and you get....

X= 45 becasue 2 times 45 equals 90

answer: X=45°

7 0

3 years ago

A researcher is interested in finding a 95% confidence interval for the mean number minutes students are concentrating on their

Sever21 [200]

Answer:

A. Normal

B. Between 40.08 minutes and 43.92 minutes.

C. About 95 percent of these confidence intervals will contain the true population mean number of minutes of concentration and about 5 percent will not contain the true population mean number of minutes of concentration.

Step-by-step explanation:

Central Limit Theorem

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

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

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

x% confidence interval:

A confidence interval is built from a sample, has bounds a and b, and has a confidence level of x%. It means that we are x% confident that the population mean is between a and b.

Question A:

By the Central Limit Theorem, a normal distribution.

Question B:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.96\frac{12}{\sqrt{150}} = 1.92$

The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.92 = 40.08 minutes

The upper end of the interval is the sample mean added to M. So it is 42 + 1.92 = 43.92 minutes

Between 40.08 minutes and 43.92 minutes.

Question C:

x% confidence interval -> x% will contain the true population mean, (100-x)% wont.

So, 95% confidence interval:

About 95 percent of these confidence intervals will contain the true population mean number of minutes of concentration and about 5 percent will not contain the true population mean number of minutes of concentration.

3 0

3 years ago

GIVING BRAINLIEST!!!PLS HELP :((

Dahasolnce [82]

Answer:

D (32, 10)

Step-by-step explanation:

30 - 5 - 5 - 5 - 5 = 10

0 + 8 + 8 + 8 + 8 = 32

5 0

3 years ago

Read 2 more answers

Line pq is the perpendicular bisector of line MN, what is QN?

GREYUIT [131]

We know that
if PQ <span>is the perpendicular bisector of line MN
then
MQ=QM
and
NP=MP
so
6x+1=10x-17----------> 10x-6x=17+1-----> 4x=18---------> x=18/4----> x=4.5

QN=2x+5-----> QN=2*4.5+5-----> QN=14

the answer is
QN is 14</span>

4 0

3 years ago