What’s the correct answer for this?

Answer:

10

Step-by-step explanation:

First multiply 9 by 2.5

Then divide 225 by 22.5

Answer: Biased sample

Step-by-step explanation:

This is a biased sample because only students with strong opinions are likely going to volunteer or show interest in representing the school at the board meeting. This sample is a voluntary type sample, and at such the conclusion is not valid. This sample is biased because a group or population of students have a higher or lower sampling probability.

Answer:

A

Step-by-step explanation:

(2,1) - only one in the table. Remember (x,y)

Answer:

Step-by-step explanation:

From the question; we are given the following inclusive frequency distribution information

Class                Frequency f

1.1-1.5                           18

1.6-2.0                         27

2.1-2.5                         31

2.6-3.0                        40

3.1-3.5                         56

3.6-4.0                        55

4.1-4.5                          23

Convert the above inclusive frequency distribution to exclusive frequency distribution with respect of the upper and lower class limit ; we have:

Class                             Frequency f

1.05 - 1.55                             18

1.55 - 2.05                           27

2.05 - 2.55                          31

2.55 - 3.05                          40

3.05 - 3.55                          56

3.55 - 4.05                          55

4.05 - 4.55                          23

Class                             Frequency f                     cf

1.05 - 1.55                             18                              18            

1.55 - 2.05                           27                               45

2.05 - 2.55                          31                               76

2.55 - 3.05                          40                               116

3.05 - 3.55                          56                               172

3.55 - 4.05                          55                               227

4.05 - 4.55                          23                               250

                                       n = 250

To determine the daily sales; we can derive that from estimated Mode by using the relation :

Estimated Mode = L + fm − fm-1(fm − fm-1) + (fm − fm+1) × w

here:

L  = the lower class boundary of the modal group

fm-1 =  the frequency of the group before the modal group

fm = the frequency of the modal group

fm+1 = the frequency of the group after the modal group

w  = the group width

However;

It is easier now to determine  the modal group (i.e the group with the highest frequency), which is 3.05 -3.55

L = 3.05

fm-1 =40

fm =56

fm+1 = 55

w = 0.5

∴[tex]mode = 3.05 + \dfrac{56 - 40 }{(56 - 40) + (56 -55)} * 0.5 \\ \\ mode = 3.05 + 0.4705 \\ \\ mode = 3.5205[/tex]

To find Median Class ; we use the formula;

Median Class = value of (n / 2)th observation

Median Class  = value of (250 / 2)th observation  

Median Class = value of 125th observation

From the column of cumulative frequency cf,

we will see that the 125th observation lies in the class 3.05-3.55.

∴ The median class is 3.05-3.55.

Thus;,  

L=lower boundary point of median class =3.05

n=Total frequency =250

cf=Cumulative frequency of the class preceding the median class =116

f=Frequency of the median class =56

c=class length of median class =0.5

[tex]Median M=L+n2-cff- c \\ \\ =3.05+125-11656⋅0.5 \\ \\=3.05+0.08036 \\ \\ =3.13036[/tex]

hence median sales = $3130.36

Answer: 4/3

Step-by-step explanation:

As you know this graph is a lemniscate

[tex]4\int\limits^1_0 {x\sqrt{1-x^{2} } \, dx =\frac{4}{3} =1.33$[/tex]

Answer:

All real numbers greater than or equal to -3

Step-by-step explanation:

First look at graph where the line points to which direction of the graph

And look for any closed or open circles in the graph

Since in the graph has a close circle at (-3,-2) meaning it includes that x-value for its domain.

With the graph going to positive infinity it states that the domain is all real numbers.

So in conclusion it has a domain of all real numbers greater than or equal to -3

Answer: 2

Step-by-step explanation:

9 × 2 - 16

18 - 16

2

Answer:

Step-by-step explanation:

Random sampling is a procedure for sampling from a population in which (a) the selection of a sample unit is based on chance and (b) every element of the population has a known, non-zero probability of being selected.

Answer:

A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen.

I hope this helped...

Answer:

655 people would need to be surveyed.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

In this question, we have that:

[tex]\pi = 0.68[/tex]

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

90% confidence level

So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].

How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%?

We need to survey n adults.

n is found when M = 0.03. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.645\sqrt{\frac{0.68*0.32}{n}}[/tex]

[tex]0.03\sqrt{n} = 1.645\sqrt{0.68*0.32}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.68*0.32}}{0.03}[/tex]

[tex](\sqrt{n})^{2} = (\frac{1.645\sqrt{0.68*0.32}}{0.03})^{2}[/tex]

[tex]n = 654.3[/tex]

Rounding up

655 people would need to be surveyed.

Answer:

E. 400

Step-by-step explanation:

So this is how we set this up, and how we solve

[tex]0.25x=100\\x=100/0.25\\x=400[/tex]

Hope this helps!

So you are solving for circumference of a quarter circle: [tex]\frac{1}{4}2 \pi r[/tex]

r= 28

[tex]\pi=3.14[/tex]

[tex]\frac{1}{4}2(87.92)=\\43.96[/tex]

Answer:

C.

Step-by-step explanation:

[tex]\frac{1}{5} +\frac{5}{6}[/tex] ≈ 1

5 + 8 + 1 = 14

Answer:

8/3

Step-by-step explanation:

6(x-2)=4

x-2=4/6

x= 8/3

Answer:

x = 8/3

Step-by-step explanation:

Use Distributive Property

6(x-2) = 4

6x -12 = 4

add 12 on both sides

6x = 16

Divide by 6

x = 8/3

In decimal form: 2.667

The answer is B..........

Answer:

B. 1

Step-by-step explanation:

If it was more than one it wouldn't be a triangle.

Answer: -6m-n+3

Step-by-step explanation:

The answer is -6m-n+3 because -3

times 2m is -6m and -n stays the same its outside of the parenthesis

and lastly -3 times -1 is positive 3

so answer maches up with the last one

the answer is -6m-n+3

Hope this helps :)

Answer:

-6m-n+3

Step-by-step explanation:

-3 x 2 is -6m (n stays same)

-3 x -1 is whole or positive 3

put it together and u get -6m-n+3

hope this helps

Answer:

385 ways

Step-by-step explanation:

Given;

7 red balls

10 white balls

In how many ways can 4 balls be selected if there are more than 2 red balls.

Selecting 4 balls which must contain more than 2 red balls, will be 3 red balls and 1 white ball to make it 4 in total, or all the 4 balls selected will red balls.

= 3 red balls and 1 white ball  OR 4 red balls

= 7C₃ x 10C₁  + 7C₄

[tex]= \frac{7!}{4!3!} *\frac{10!}{9!1!} \ \ + \ \frac{7!}{3!4!} \\\\= (35*10) \ + \ 35\\\\= 350 \ + 35\\\\= 385 \ ways[/tex]

Therefore, there are 385 ways of selecting 4 balls, if there are more than 2 red balls.

Answer:

Step-by-step explanation:

Confidence interval for the difference in the two proportions is written as

Difference in sample proportions ± margin of error

Sample proportion, p= x/n

Where x = number of success

n = number of samples

For the first brochure,

x = 100

n1 = 500

p1 = 100/500 = 0.2

For the second brochure

x = 125

n2 = 500

p2 = 125/500 = 0.25

Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.95 = 0.05

α/2 = 0.05/2 = 0.025

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.025 = 0.975

The z score corresponding to the area on the z table is 1.96. Thus, the z score for confidence level of 95% is 1.96

Margin of error = 1.96 × √[0.2(1 - 0.2)/500 + 0.25(1 - 0.25)/500]

= 1.96 × √0.000695

= 0.052

Confidence interval = (0.2 - 0.25) ± 0.052

= - 0.05 ± 0.052

Functions

Vertical Line Test

Let's see what we are given.

We are given a graph of an inverse of a function.

We need to figure out whether the graphed inverse function is a function or not.

By the definition of a function, we know that every x input must correlate with one y output. In layman's terms, each respective x input has its own specific y output.

This definition builds the foundation of the Vertical Line Test. We can use this simple "tool" to verify whether or not a given graph is a function or not.

When we apply the Vertical Line Test to the graphed inverse function, we can see that every x input has only one specific y output.

∴ we can conclude that the graphed inverse function is indeed a function.

The answer to the question would be A. True.

___

Learn more about functions: https://brainly.com/question/30017262

Learn more about Algebra I: https://brainly.com/question/17011730

___

Topic: Algebra I

Unit: Functions

Answer:

Car: 60%

Motorcycle: 30%

Truck: 10%

Step-by-step explanation:

Car: [tex]\frac{12}{12+6+2} =\frac{12}{20} =\frac{60}{100}[/tex] or 60%

Motorcycle: [tex]\frac{6}{12+6+2} =\frac{6}{20} =\frac{30}{100}[/tex] or 30%

Truck: [tex]\frac{2}{12+6+2} =\frac{2}{20} =\frac{10}{100}[/tex] or 10%

Answer:[tex]y=-\frac{3}{2} x+12[/tex]

Step-by-step explanation:

Perpendicular lines have inversely proportional slopes. So make the slope negative and switch it to its reciprocal.

2/3x would change into -3/2x

Lets write that down for a starting point for our perpendicular line.

y = -3/2x + b

We were given the x and y value via the coords. x = 12 and y = -6

Now we have -6 = -3/2(12) + b. Multiply -3 and 12 to get -36, then divide by 2 to get -18.  Now it's -6 = -18 + b. Solve for b by adding 18 to both sides to get b = 12

The value of X is 4

please see the attached picture for full solution

Hope it helps

Good luck on your assignment..

Answer:

[tex] ME =z_{\alpha/2} \frac{\sigma}{\sqrt{n}}[/tex]

The confidence level is 0.98 and the significance is [tex]\alpha=1-0.98 =0.02[/tex] and [tex]\alpha/2 =0.01[/tex] and the critical value using the table is:

[tex]z_{\alpha/2}= 2.326[/tex]

And replacing we got:

[tex] ME=2.326 \frac{425}{\sqrt{22}}= 210.760\ approx 210.76[/tex]

Step-by-step explanation:

For this case we have the following info given:

[tex]\sigma = 425[/tex] represent the population deviation

[tex] n =22[/tex] the sample size

[tex]\bar X =1520[/tex] represent the sample mean

We want to find the margin of error for the confidence interval for the population mean and we know that is given by:

[tex] ME =z_{\alpha/2} \frac{\sigma}{\sqrt{n}}[/tex]

The confidence level is 0.98 and the significance is [tex]\alpha=1-0.98 =0.02[/tex] and [tex]\alpha/2 =0.01[/tex] and the critical value using the table is:

[tex]z_{\alpha/2}= 2.326[/tex]

And replacing we got:

[tex] ME=2.326 \frac{425}{\sqrt{22}}= 210.760\ approx 210.76[/tex]

Answer:

Finding 1/5 of something is the same as dividing that number by 5. Since 24 isn't divisible by 5, 24 / 5 is not an integer. Since you can't have 4.8 species of animals the answer to (a) is no.

For (b), 1/3 * 24 = 8 and 24 - 8 = 16.

Answer:

answer d) 20

Step-by-step explanation:

Because the two lines are parallel two by two, the figure is a parallelogram.

In a parallelogram the opposite corners are identical.

Given:

opposite corner1 = 130°

opposite corner2= (6a + 10)°

Because corner1 = corner2 we now have:

(6a + 10) = 130

6a + 0 = 130 -10

6a = 120

a = 20

Which is answer d).

Answer:

C............PAC-MAN

Step-by-step explanation:

Answer:

Step-by-step explanation:

it is -12 because -6 plus -6 is also like 6 plus 6

and then you have to add the negative Sign.

pls brainliest me

-6 - 6 = - 12

Happy to help! Please mark as the brainliest!

Answer:

Answers below

Step-by-step explanation:

a. Is x​ (approximately) a binomial random​ variable?

b. Give the probability distribution for x as a formula.

c. Find p(x = 2).

d. Find P(x <= 1).

Answer:

Equilateral, acute

Step-by-step explanation:

Equilateral triangles have all sides the same length (all sides are 4 ft in this triangle, so it is equilateral).

Acute triangles have no angles that are greater than or equal to 90 degrees (all angles are 60, which is less than 90, so it is acute).

Answer:

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

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

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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.

In this question:

[tex]\mu = 152, \sigma = 14.5[/tex]

The z-score when x=187 is ...

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{187 - 152}{14.5}[/tex]

[tex]Z = 2.41[/tex]

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.

Answer:

A-8

Step-by-step explanation:

Any other higher number plugged in makes the equation false

Answer:

So we can use geometric progression each time multiplying by 0.0475

so thats (275*0.0475)*10

So that means that we would get

130.625 so we subtract that from 275

275-130.625=144.375

That would be

Step-by-step explanation: