What is the equation of a line with a slope of −4 and a point (−2, 5) on the line?

Which of the choices below is not a possible correlation coefficient?

fiasKO [112]

Answer:

The condition for r is the following:

$-1 \leq r \leq 1$

And for this case if we analyze the options the only impossible value is given by:

1.0528

Because this value is higher than 1 and not satisfy the general limits for r

Step-by-step explanation:

The correlation coefficient is a measure of dispersion and is a value between -1 and 1, and is defined as:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

The condition for r is the following:

$-1 \leq r \leq 1$

And for this case if we analyze the options the only impossible value is given by:

1.0528

Because this value is higher than 1 and not satisfy the general limits for r

8 0

3 years ago

A researcher reports survey results by stating that the standard error of the mean is 25 the population standard deviation is 40

bezimeni [28]

Answer:

a) A sample of 256 was used in this survey.

b) 45.14% probability that the point estimate was within ±15 of the population mean

Step-by-step explanation:

This question is solved using the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

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.

a. How large was the sample used in this survey?

We have that $s = 25, \sigma = 400$ . We want to find n, so:

$s = \frac{\sigma}{\sqrt{n}}$

$25 = \frac{400}{\sqrt{n}}$

$25\sqrt{n} = 400$

$\sqrt{n} = \frac{400}{25}$

$\sqrt{n} = 16$

$(\sqrt{n})^2 = 16^2[tex][tex]n = 256$

A sample of 256 was used in this survey.

b. What is the probability that the point estimate was within ±15 of the population mean?

15 is the bounds with want, 25 is the standard error. So

Z = 15/25 = 0.6 has a pvalue of 0.7257

Z = -15/25 = -0.6 has a pvalue of 0.2743

0.7257 - 0.2743 = 0.4514

45.14% probability that the point estimate was within ±15 of the population mean

3 0

3 years ago

Angle D=(7b+1) angle E=(2b+1) and angle F=(b+8) what is the measure of angle E

Mademuasel [1]

angleD=(7b+1)angle E=(2b+1)and angle F=(b+8)

3 0

3 years ago

Read 2 more answers

Jeanetta collects antique picture frames. In her first year of collecting, she collects 10 frames. Each year, she hopes to colle

GREYUIT [131]

Answer:

235

Step-by-step explanation:

5 0

2 years ago

A bolt has 6 1/2 turns per inch. How many turns would be in 2 1/2 inches of threads?

Reika [66]

There would be 41 1/4 turns in 2 1/2 inches of threads.

Given, number of turns a bolt has = 16 1/2 turns per inch.

per inch bolt turns = 16 1/2 =33/2

how many turns would be there in 2 1/2 inches of threads = ?

Threads Per Inch, or TPI, is a measure of how many threads are found in one inch along a fastener's length. American fasteners are the only ones that employ TPI. Typically, the thread count is higher for smaller fasteners since they have finer threads. Just as the name implies, the Threads Per Inch (TPI) refers to the number of threads that run the length of a screw for one inch. The TPI of a screw can be easily calculated by simply counting the threads and dividing the total length.

so, 5/2 inches bolt turns =33/2 x 5/2

=165/4

hence 41 1/4 turns

Therefore, 2 1/2 inches of threads have 41 1/2 turns.

Learn more about Conversions here:

brainly.com/question/16851332

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4 0

10 months ago

​What is the equation of a line with a slope of ​ ​ −4 ​ ​ and a point ​ (−2, 5) ​ on the line?

What is the equation of a line with a slope of −4 and a point (−2, 5) on the line?