1. What is the purpose of using a control group and an experimental group in a research study? Give an
example of a situation where they would be used.

Answers

Answer 1

Answer:

A control group is used in an experiment as a point of comparison.

Step-by-step explanation:

By having a group that does not receive any sort of treatment, researchers are better able to isolate whether the experimental treatment did or did not affect the subjects who received it.


Related Questions

If the radius is 8m, what is the diameter​

Answers

Answer:

16m

Step-by-step explanation:

radius is half of diameter​

Find the value of k that makes the function continuous

Answers

Answer:

13/3

OR

4.33333

Step-by-step explanation:

For this function to be continuous, the second function must have the value of the limit as x approaches 3 of the first function.

To find [tex]\lim_{x \to 3} \frac{2x^2-3-15}{x-3}[/tex] we have to factor the top of the fraction

2x^2 - 3 -15

2x^2 - 18

2* (x^2 - 9)

2 * (x + 3) (x - 3)

this is perfect because this cancels out the x - 3 on the bottom

so the function become f(x) = 2 * (x + 3)

When 3 is plugged in it becomes 2 * (3 + 3) = 2 * 6 = 12

Now if you plug in 3 to the second function and make it equal to 12, you can find the value of k.

k*(3) - 1 = 12

k*3 = 13

k = 13/3

k = 4.33

Which equation can be used to find A, the area of the parallelogram shown? A = 5 × 9 A = 4 × 9 A = 12 × 5 × 9 A = 12 × 4 × 9

Answers

Answer:

I believe it's A=5 times 9 but since the triangle is special (3-4-5), it could be 12 times 5. Hope this kinda help :)

The sum of three consecutive positive numbers is 147. Find the product of the greatest and the
smallest number.

Answers

Answer:

any how there are three consecutive positive numbers

URGENT PLZ HELP

Solve for x. Assume that lines which appear to be diameters are actual diameters.

Answers

Answer:

Step-by-step explanation:

This is a central angel so the degree of the angle is equal to the degree of the arc which is 111.

X+114=111

add negative -114 to each side to get X alone.

-114+X+114= 111+-114

X=-3 .   Answer negative 3

There are 4 oranges, 7 bananas, and 5 apples in a fruit basket.
Ignacio selects a piece of fruit at random and then Terrance
selects a piece of fruit at random.

probability of two bananas
p( two bananas )​

Answers

Pretty low, it’s exactly 0.175

Can anyone help me with my homework

Answers

GFBH is the code

1 is -3,-2 which is G
2 is 3,4 which is F
3 is 2,0 which is B
4 is 1,-3 which is H

Use slopes and y-intercepts to determine if the lines 4x−3y=6 and y=43x−1 are parallel.

Answers

Answer:

Since they have the same slope, they are parallel.

Step-by-step explanation:

Equation of a line:

The equation of a line has the following format:

[tex]y = mx + b[/tex]

In which m is the slope. If two lines are parallel, they have the same slope.

4x−3y=6

Placing into the above format:

[tex]3y = 4x - 6[/tex]

[tex]y = \frac{4x - 6}{3}[/tex]

[tex]y = \frac{4x}{3} - 2[/tex]

The slope [tex]m = \frac{4}{3}[/tex]

y=4/3x−1

The slope is [tex]m = \frac{4}{3}[/tex]

Since they have the same slope, they are parallel.

Which expression is equivalent to 4(-2c) - c

-6c

8c - 1

-9c

7c + 1
I'm not good at this stuff -_-

Answers

Answer:

none of those?

Step-by-step explanation:

4(-2c) = -8c

Answer:    -9c

Step-by-step explanation:

4(-2c) - c

= -8c - c

= -9c  

-9c is the answer

Find the value of x 116 degrees and 33 degrees

Answers

Answer:

x = 31 degrees

Step-by-step explanation:

This is a triangle because there are 3 angles so they all add up to 180 degrees.

116 + 33 + x + 180   Add 116 and 33

149 + x = 180    subtract both sides by 149

x = 31

A rectangle with an area of 61 units” is dilated by a scale factor of ;. Find the area of
the rectangle after dilation. Round your answer to the nearest lenth, if necessary.

Answers

Answer:

34 units

Step-by-step explanation:

I decided that one side is 61 units and the other is 1 unit, since that would make the area 61 units.

Then I multiplied 61 by 3/4, which equals a new length of 45.75 units, and I also multiplied 1 by 3/4, which equals a new length of 0.75 units.

Finally, I solve for the area of the rectangle:

45.75 x 0.75 ≈ 34 units (rounded to the nearest whole number)

The diameter of the washers are required to be between 1.53 millimeters and 1.65 millimeters long. Any washers that do not meet this requirement must be discarded. What percentage of washers will the factory have to discard

Answers

Answer:

32%

Step-by-step explanation:

Let x be the mean of the values and σ their standard deviation.

Since the minimum value of the diameter of the washers is 1.53 mm, then

x - σ = 1.53 mm  (1)

Also, the maximum value of the diameter of the washers is 1.65 mm, then

x + σ = 1.65 mm  (2)

Adding (1) and (2), we have

x - σ = 1.53 mm

+

x + σ = 1.65 mm  

2x = 3.18

x = 3.18/2

x = 1.59 mm

Subtracting (1) and (2), we have

x - σ = 1.53 mm

-

x + σ = 1.65 mm  

-2σ = -0.12

σ = -0.12/-2

σ = 0.06 mm

Since the diameter of the washers are required to be between 1.53 millimeters and 1.65 millimeters long, and x - σ = 1.53 mm to x + σ = 1.65 mm are the required values, 68% of the washers lie in this range. The other values lie outside this range. The amount that the factory would have to discard is 100% - 68% = 32%

This question is based on the percentage. Thus, 32%  of washers will the factory have to discard.

Given:

The diameter of the washers are required to be between 1.53 millimeters and 1.65 millimeters long.

We need to determined the percentage of washers will the factory have to discard.

According to question,

Let x be the mean and σ be their standard deviation.

The minimum value of the diameter of the washers is 1.53 mm.

Then,

x - σ = 1.53 mm  (1)

Also, the maximum value of the diameter of the washers is 1.65 mm, then

x + σ = 1.65 mm  (2)

Adding (1) and (2), we have

   x - σ = 1.53 mm  

+  x + σ = 1.65 mm  

⇒ 2x = 3.18

We get,

x = 1.59 mm

Subtracting (1) and (2), we have

 x - σ = 1.53 mm

- x + σ = 1.65 mm  

⇒ -2σ = -0.12

We get,

σ = 0.06 mm

Therefore, the diameter of the washers are required to be between 1.53 millimeters and 1.65 millimeters long, and x - σ = 1.53 mm to x + σ = 1.65 mm are the required values, 68% of the washers lie in this range.

And the other values lie outside this range. The amount that the factory would have to discard is 100% - 68% = 32%.

Thus, 32%  of washers will the factory have to discard.

For more details, prefer this link:

https://brainly.com/question/13703753

Create a probability model for the outcome of flipping a coin 3 times. what is the probability of landing on heads at least once
a. 2/3
b. 1/2
c. 7/8
d. 1/8

Answers

Answer:

it is A.2/3

Step-by-step explanation:

12+x=46
what is the answer to x?

Answers

Answer:

x=34

Step-by-step explanation:

hey so i need help on my khan so please please please help

Answers

Answer:

Step-by-step explanation:

A process manufactures ball bearings with diameters that are normally distributed with mean 25.14 mm and standard deviation 0.08 mm. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A particular ball bearing has a diameter of 25.2 mm. What percentile is its diameter on

Answers

Answer:

The diameter is in the 77th percentile.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be 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.

25.14 mm and standard deviation 0.08 mm.

This means that [tex]\mu = 25.14, \sigma = 0.08[/tex]

A particular ball bearing has a diameter of 25.2 mm. What percentile is its diameter on?

This is the pvalue of Z when X = 25.2. So

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

[tex]Z = \frac{25.2 - 25.14}{0.08}[/tex]

[tex]Z = 0.75[/tex]

[tex]Z = 0.75[/tex] has a pvalue of 0.77.

The diameter is in the 77th percentile.

what is the value of x when h(x) x-3

Answers

Answer:

-1

Step-by-step explanation:

I did it in my review

Answer:
x= -3/h

hope this helps :)

In a survey of consumers aged 12 and​ older, respondents were asked how many cell phones were in use by the household.​ (No two respondents were from the same​ household.) Among the​ respondents, answered​ "none," said​ "one," said​ "two," said​ "three," and responded with four or more. A survey respondent is selected at random. Find the probability that​ his/her household has four or more cell phones in use. Is it unlikely for a household to have four or more cell phones in​ use? Consider an event to be unlikely if its probability is less than or equal to 0.05.
​P(four or more cell ​phones)
​(Round to three decimal places as​ needed.)

Answers

Consider an event to be unlikely if its probability is less than or equal to 0.05.
204+287+376+137+130=1134

130/1134= .115


No​, because the probability of a respondent with four or more cell phones in use is greater than 0.05.

What percent of 84 is 42

Answers

Sorry if I’m wrong but i believe it’s 50.

A customer service representative must spend different amounts of time with each customer to resolve various concerns. The amount of time spent with each customer can be modeled by the following distribution : X~Exp (0.2)
Find the quartile 3. Round to the nearest tenth.

Answers

Answer:

The quartile 3 is 0.3

Step-by-step explanation:

Exponential distribution:

The exponential probability distribution, with mean m, is described by the following equation:

[tex]f(x) = \mu e^{-\mu x}[/tex]

In which [tex]\mu = \frac{1}{m}[/tex] is the decay parameter.

The probability that x is lower or equal to a is given by:

[tex]P(X \leq x) = \int\limits^a_0 {f(x)} \, dx[/tex]

Which has the following solution:

[tex]P(X \leq x) = 1 - e^{-\mu x}[/tex]

The probability of finding a value higher than x is:

[tex]P(X > x) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-\mu x}[/tex]

X~Exp (0.2)

This means that [tex]m= 0.2, \mu = \frac{1}{0.2} = 5[/tex]

Find the quartile 3.

The 3rd quartile is the 75th percentile, for which [tex]P(X \leq x) = 0.75[/tex], or [tex]P(X > x) = 1 - 0.75 = 0.25[/tex]

Since

[tex]P(X > x) = e^{-\mu x}[/tex]

[tex]e^{-5x} = 0.25[/tex]

[tex]\ln{e^{-5x}} = \ln{0.25}[/tex]

[tex]-5x = \ln{0.25}[/tex]

[tex]x = -\frac{\ln{0.25}}{5}[/tex]

[tex]x = 0.277[/tex]

Rounding to the nearest tenth, the quartile 3 is 0.3.

100
400 people were surveyed
about their eye color. 8% of
the people surveyed have
green eyes. How many
people had green eyes?

Answers

Answer:

32 people

Step-by-step explanation:     If there are 400 people and there is 8% of that, then first convert 8% to a decimal so its easier to work with. The multiply with 400:

0.08 * 400 = 32

Answer: 32 people have green eyes

32 people have green eyes

Find the mean, median, mode, and range of the following data set.

15, 12, 19, 15, 16, 13, 15.

Mean:

Median:

Mode:

Range:

Answers

12 13 15 15 15 16 19

mean: 15

median: 15

mode: 15

range: 7

Answer:

12, 13, 15, 15, 15, 16, 19

Step-by-step explanation:

Mean: 15

Median: 15

Mode: 15

Range: 7

Question 2
There are 8 students in a discussion section: 3 boys and 5 girls.
If the teacher picks a group of 1 at random, what is the probability that everyone in the
group is a boy?
3/8
1/3
110
Submit answer
Exit
wl
Chin

Answers

Answer:

3/8

Step-by-step explanation:

this is because there are 8 students in all and only three of them are boys

Rewrite the number in Standard form
6 x 10^8

Answers

Answer:

10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 100,000,000 x 6 = 600,000,000.

Answer:

600000000

Step-by-step explanation:

10^8=100000000

6×100000000=600000000

hope this helps

how many 1/3 inch cubes does it take to fill a box with width 2 2/3 inches length 3 1/3 inches and height 2 1/3 inches

Answers

Answer:

560/9 or around 63 cubes

Step-by-step explanation:

2 2/3 -> 8/3

3 1/3 -> 10/3

2 1/3-> 7/3

7/3 x 8/3= 56/9

56/9 x 10/3 = 560/27

560/27 divided by 1/3

= 560/9

PLS HELP I WILL GIVE BRAINLYEST

Answers

Answer:

hey

Step-by-step explanation:

pls help me then i help u

Write 5x – 4y = 10 in slope-intercept form

Answers

y=5/4x + 5/2 hope this helped

5 1/3 + (2 2/3 + 1 1/3)

Answers

answer: 9 and 1/3!! brainliest are appreciated

Math Which expressions represent 9 divided by the sum of 1 and 2? Check all that are true. 09/(1+2) 9+1+2 I (9 - 1) + 2 (1 + 2) = 9 09+ (1 + 2)​

Answers

Answer: 9/(1+2)

Hope it helps :)

I need help with the questions I circle only.

Answers

Answer:

3:12

4:36

Step-by-step explanation:

( pls dont report me let me kno if it wrong and i will fix it

Not SUV= 12

I didn’t get the last one
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