For each of the following cases [(a), (b), and (c)], (I) state whether the study should be observational or experimental. (II) state whether the study should be run blind, doubleblind, or neither. If the study should be run blind or double-blind, who should be blinded?(a) An investigation of whether taking aspirin reduces one’s chance of having a heart attack.(b) An investigation of whether babies born into poor families (family income below $25,000) are more likely to weigh less than 5.5 pounds at birth than babies born into wealthy families (family income above $65,000).(c) An investigation of whether the size of the midsagittal plane of the anterior commisssure (a part of the brain) of a man is related to the sexual orientation of the man.

Answers

Answer 1

Answer:

(a) An investigation of whether taking aspirin reduces one’s chance of having a heart attack.

Experimental

Neither blind nor double-blind (unless a placebo is being administered to some participants).

(b) An investigation of whether babies born into poor families (family income below $25,000) are more likely to weigh less than 5.5 pounds at birth than babies born into wealthy families (family income above $65,000).

Observational

There is no blinding issue here.

(c) An investigation of whether the size of the midsagittal plane of the anterior commissure (a part of the brain) of a man is related to the sexual orientation of the man.

Observational

There is no blinding issue here.

Step-by-step explanation:

An observational study happens where some variables are observed to determine their correlations.   On the other hand, in experimental studies, the researcher controls certain variables to determine causality.  Therefore, an experimental study provides evidence of cause and effect, like in (a) above.


Related Questions

Pls help I don’t know how to do this.

Answers

Answer:

If they are across from each other the angles are the same so divide 81 by 3 and thats your x value, so its 27

1. Diane's Sweet Treats can make 24 cupcakes using 16 ounces of whipped
icing. How much icing is used on each cupcake?
a. 1/6 ounce of icing per cupcake.
b. 2/3 ounce of icing per cupcake.
c. 1/2 ounce of icing per cupcake.
d. 3/4 ounce of icing per cupcake.

Answers

Answer:

b. 2/3 ounce of icing per cupcake.

Step-by-step explanation:

 Given parameters:

       Number of cupcakes = 24 cupcakes

        Ounces of whipped icing = 16 ounces

Unknown:

How much icing was used in each cupcake  = ?

Solution:

 To find the number icing used per cupcake;

                             = [tex]\frac{number of ounces of whipped icing}{Number of cupckakes}[/tex]

  Input the parameters;

                              = [tex]\frac{16 ounce of icing }{24 cupcake}[/tex]

                             = [tex]\frac{2}{3}[/tex] ounce of icing per cupcake

If f(x) = 2x2 + x-1, then f(-5)
= ?

Answers

Answer:

-54

Step-by-step explanation:

(-5)^2 = -25

2(-25)+ -5 +1 =-54

Answer:

f(-5) = -2

Step-by-step explanation:

f(-5) = 2x2 + -5 -1

f(-5) = 4 - 6

f(-5) = -2

Which of the following could be the ratio between the lengths of the two legs
of a 30-60-90 triangle?
Check all that apply.
OA. VE2
✓ B. 1: 13
C. 5 : 13
OD. 2.5: 6
E. 1: 2
OF. : 3

Answers

Answer:1 squad 3

2 squad 3 :6

Step-by-step explanation:

Simplify the algebraic expression by combining like (or similar) terms.
5+9x+2

Answers

Answer:

7 + 9x

Step-by-step explanation:

add 5 and 2 and 9x doesn't have a like term so it stays the same

Answer:

9x + 7

Step-by-step explanation:

Like terms are terms that have the same variables and powers. Here, for 9x, there is no other term that is multiplied by x. So, the only terms we can combine is 2 and 5 which leaves us with 9x+7.


Factorise fully
10c + 25​

Answers

Answer:

5(2c+5)

I hope this helps

Fifty students are going on a field trip. Twenty of the students are boys. What percent of the students are girls?

Answers

Answer:

60% would be the correct answer

Step-by-step explanation:

The girls percentage among students is 60%.

What is a percentage?

A percentage is a proportion that shows a number as parts per hundred. If we have to calculate percent of a number, divide the number by the whole and multiply by 100.

For the given situation,

Total number of students = 50

Number of boys = 20

Number of girls = [tex]50-20[/tex]

⇒ [tex]30[/tex]

Thus, girls percentage is

⇒ [tex]\frac{30}{50}(100)[/tex]

⇒ [tex]60[/tex]

Hence we can conclude that the girls percentage among students is 60%.

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Carson's pool is leaking at a rate of 18 gallon of water every 14 hour. If the leak continues at the same rate, how much water will have leaked from Carson's pool after 1 hour?

Answers

1.285 gallons of water

Answer:

1 gallon water has leaked

Step-by-step explanation:

$46.76 for 4 pounds. What is the price per pound?

Answers

9514 1404 393

Answer:

  $11.69 per pound

Step-by-step explanation:

To find price per pound, divide price by pounds:

  $46.76/(4 lb) = $11.69/lb

Find the slope of the line passing through the points (5,6) and (5,-4).

Answers

Answer:

subtract -4-6/5-5

Step-by-step explanation:

Answer is no solution

PLEASE HERRy i have to finish

Answers

I think it’s but I’m not sure E

Answer:

:)

Step-by-step explanation:

Which set of ordered pairs represents a function?
o{(1,3) (2,5) (4,9) (4, 13)}
o{(1,3) (1,5) (4, 9) (6,3)}
o {(1, 3) (2,5) (2, 9) (6, 13)}
O {(1,3) (2,5) (4, 9) (6,5)}

Answers

Answer:

The answer is D

Step-by-step explanation:

2.6586 divided by 0.633

Answers

Answer:

4.2

Step-by-step explanation:

The answer would 4.2
2.6586 divided by 0.633 equals 4.2

helpppppppppppppppppppp

Answers

answer: 8.40049 × 10^7

The midpoint of xy is located at the origin

Answers

Answer:

Is there supposed to be an image?

Step-by-step explanation:

Ritika bought 5 meters of cloth from the market. She cut off 2 3/4 meters and gave it to Aditi. What length of cloth is left with her?

Answers

Answer:

I think its 3/2

hope it will help you

To solve the problem -9 + 18 what is the first step?
a. KCO (keep change fli[p)
b. Subtract 18 - 9
c. Subtract 9 - 18
d. Add 9 + 18

Answers

Answer:

Step-by-step explanation:

x+12x-13 = 0 and azo, what
is the value x+lo?​

Answers

Wat this doesn’t make sense

Answer please ? Find the perimeter of the figure ( must include all sides )

Answers

Answer:

32 ft

Step-by-step explanation:

First we can add up all the sides we already know as perimeter is the sum of all the lengths of a shape. 9+6+3+4 = 22

There are two unknown side lengths in the diagram, the long one at the top, and the short one between the 3ft side and the 4ft side. Luckily these can be easily found using the given sides. Since this shape is rectangular in nature (all 90-degree angles), the top length is the same as the bottom length. We know the total bottom length to be 7ft (3+4) so the top length must be 7ft as well.

Similarly, all the vertical lengths on the right side must be equal to the 9ft length on the left side, therefore the unknown length is 3ft (9-6).

Adding on these two new lengths and our total perimeter is 22+7+3 = 32ft.

Hope this helped!

Help:(
At a manufacturing plant where switches are made, it is a known fact that 2% of all switches are defective. If two
switches are used in a device, what is the probability that both switches are good?
0.9604
b. 0.02
C. 0.98
d. 49

Answers

Answer:

A) 0.9604

Step-by-step explanation:

Because it is.

Find the value of 45\75=5

Answers

Answer:

.6

Step-by-step explanation:

whats 2 plus 2? do u know?

Answers

I think it might be 4.. I’m not sure tho

Consider the line -7x - 5y=4.

Answers

y= 4+7x/-5 is the answer of you're asking to solve

Melody is factoring the expression x^3 - 2x^2 + 4x - 8. Her first two steps are shown.

x^3 - 2x^2 + 4x - 8 = x^2(x - 2) + 4(x - 2)
= (x^2 + 4)(x - 2)

What should Melody do next to finish factoring the expression?

A. Melody has completely factored the expression.

B. Melody should rewrite (x^2 + 4) as (x - 2)^2

C. Melody should rewrite (x^2 + 4) as (x - 2)(x + 2)

D. Melody should rewrite (x^2 + 4) as (x + 2)^2

Answers

Answer:

A, melody completed factoring

Step-by-step explanation:

Melody has completely factored the expression which is correct option(A).

What is expression?

Expressions is the defined as mathematical statements that have a minimum of two terms containing variables or numbers.

Given the expression,

⇒ x³ - 2x² + 4x - 8

⇒ x²(x - 2) + 4(x - 2)

⇒ (x² + 4)(x - 2)

So, factors of given expression are (x² + 4)  and (x - 2).

Hence, Melody has completely factored the expression.

Learn more about expression here:

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Zach mows lawns. He charges $5 plus $3 per hour. Alex also mows lawns He charges $2 plus $4 per hour. How many hours do they need to work to make the same amount

Answers

Answer:

They both need to work 3 hours to get the same amount of $14.

Step-by-step explanation:

If you have a graphing calculator handy, just graph the two expressions 3x + 5 and 4x + 2 and look for the point where they intersect. If you don't have a graphing calculator set up the equation 3x + 5 = 4x + 2. Subtract 4x from both sides to get -x + 5 = 2. Then subtract 5 from both sides to get -x = -3. Since x shouldn't be negative, divide both sides by -1. You do this because just like x is 1x, -x is -1x. After dividing, you should get x = 3.

(11 points!) PLEASEEEEEEEEE Find the value of x for numbers 6,7,8,and 9 and please attach work or a good explanation thank you sm in advance!❤️

Answers

(6) 2xº = 86º  ==>  x = 43

(7) 108º = 3xº  ==>  x = 36

(8) 72º = 4xº  ==>  x = 18

(9) 111º = (x + 21)º  ==>  x = 90

Answer:

1.

2x=86

x=43

2.

3x=108

x=36

3.

4x=72

x=18

4.

x+21=111

x=90

-5 is a rational number and an integer yes or no

Answers

Answer:

Yes

Step-by-step explanation:

Integers are whole numbers that are positive and negative. Since -5 is an integer then is also a rational number because all integers are rational numbers

Ns. Moore drove 200 miles in February. She drove 8 times as many miles in March as she did in January. How many mailed did Ms. Moore drive in March

Answers

Answer:

25

Step-by-step explanation:

200 divided by 8

A 190-second song is divided into 3 parts, the beginning, the middle, and the end. The beginning is 1/6 as long as the end. The middle part is 1/2 as long as the end. Find the length of each part.

The beginning is ____ seconds
The middle is _____ seconds
The end is ______ seconds

Answers

Answer:

The beginning part is 19 seconds.

The middle part is 57 seconds.

The end part is 114 seconds.

Step-by-step explanation:

First, you have to form expressions. Let the end part be x :

Beginning = (1/6)x

Middle = (1/2)x

End = x

Next, you have to add up altogether equals to 190 :

(1/6)x + (1/2)x + x = 190

(5/3)x = 190

x = 190 ÷ (5/3)

x = 114 s

Lastly, you have to substitute the x-value into the expressions :

Beginning = (1/6)(114) = 19 s

Middle = (1/2)(114) = 57 s

End = 114 s

Answer:

b is 19 seconds

m is 57 seconds

e is 114 seconds

Step-by-step explanation:

total = b + m + e

total = 1/6e + 1/2e + e

190 = 1/6e + 1/2e + e

190 = 10/6e

190 * 3/5 = e

114 = e

(1/6)e = b = (1/6)(114) = 19

(1/2)e = m = (1/2)(114) = 57

Best estimate of the total spent, not including tax 6.52 + 19.89 + 21.15

Answers

Answer:

47.56

Step-by-step explanation:

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