1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Finger [1]
2 years ago
12

A new cream was developed to reduce the irritation caused by poison ivy. To test the effectiveness, researchers placed an ad onl

ine asking volunteers to participate in the study, and 100 subjects replied. They are informed that one group will receive a new cream and the other group will receive a cream with no active ingredient. The researchers believe that sun exposure may affect the cream’s effectiveness. The subjects are then asked about their outdoor activity, and 42 of the subjects state they spend more than 50% of their day outside. The 42 subjects are randomly assigned to the two treatments. The remaining 58 subjects are also randomly assigned to the two treatments. All subjects are exposed to poison ivy and given their cream. They are asked to return in three days and report their level of irritation.
Is this a randomized block design?

A.) Yes, the subjects could be randomly assigned to two different treatments.
B.) Yes, the participants are grouped by sun exposure, and then both treatments are randomly assigned within each group.
C.) No, the groups have an equal number of subjects.
D.) No, the subjects were not paired by age to determine if it affected the cream’s effectiveness.
Mathematics
2 answers:
andreyandreev [35.5K]2 years ago
7 0

Answer:

B: Yes, the participants are grouped by sun exposure, and then both treatments are randomly assigned within each group.

Step-by-step explanation:

Randomized block design is one in which the experimental units are categorized into groups which we call blocks. Thereafter, treatments will be randomly allocated to the experimental units inside each of the blocks.

Now, from the question, we can see that they were grouped in Blocks according to their outdoor activity which is degree of exposure to the sun. Thereafter the individual groups are randomly assigned treatments.

Thus, Option B is correct.

Zarrin [17]2 years ago
3 0

Answer:

b

Step-by-step explanation:

You might be interested in
The numbers in this chart represent the weights in kilograms of five
Nitella [24]
John’s is the outlier
3 0
3 years ago
Read 2 more answers
Number 1 has a picture
MA_775_DIABLO [31]
Question 1

cos(C) = adj/hyp
cos(C) = BC/AC
cos(C) = 15/17

Answer: Choice C) 15/17

=============================================

Question 2

sin(E) = opp/hyp
sin(E) = FD/DE
sin(E) = 24/25

So angle E is the answer

=============================================

Question 3

AC is the adjacent side to the given angle A = 33 degrees
AB = 14 is the hypotenuse

cos(angle) = adjacent/hypotenuse
cos(33) = x/14
14*cos(33) = x
x = 14*cos(33)
x = 11.741
x = 11.7

Answer: 11.7

=============================================

Question 4

x = length of board

cos(angle) = adj/hyp
cos(55) = 6/x
x*cos(55) = 6
x = 6/cos(55)
x = 10.46068
x = 10.5

Answer: 10.5

=============================================

Question 5

112 is the adjacent side to the given angle 62 degrees
x = height of building, which is the opposite leg

tan(angle) = opp/adj
tan(62) = x/112
112*tan(62) = x
x = 112*tan(62)
x = 210.641364
x = 210.6

Answer: 210.6
3 0
3 years ago
Brandon has two credit cards and would like to consolidate the two balances into one balance on the card with the lower interest
galben [10]
The correct answer is <span>c. $256.32.</span>
3 0
3 years ago
Read 2 more answers
PLEASE HELP I WILL GIVE BRAINLEST
nadya68 [22]

OK.  All the work is in the attached drawing.

Please spend enough time with it to understand what was done and how, so that you can do the next problem like this one completely on your own.

Good luck !

==============================

Here's a picky pickypoint to think about concerning the "cost".  I'm not quite sure what to do about this:

The initial, one-time $55 is a "deposit".  If she doesn't smash the bike or steal it, she gets the $55 back when she returns the bike.  

So if she eventually gets the $55 back, <u><em>is it a cost</em></u> ? ?  I don't know how to think about it.

She does need to <em>give</em> them the $55 at the beginning, just to take the bike out.  So she has to have it with her and give it to them temporarily, even though she'll  get it back, and she'll still have it when she returns home.

So here's the story:  

-- While she HAS the bike, the graph correctly shows all the money she needs, in order to get the bike, and keep it for however long she keeps it.

-- Finally, at the end of the week, after she returns the bike and gets her $55 back, the line and everything on the graph will shift down by $55.  The line will start at zero, and the little red ordered pairs will also shift straight down and still be on the line.

To put it one more way:

-- While Jen has the bike, the y-intercept of the graph is $55.

-- After she returns the bike in good condition, the y-intercept is zero.

6 0
3 years ago
Evaluate i^31 please help
Nadya [2.5K]

ANSWER

{i}^{31}  =  - i

EXPLANATION

We want to evaluate

{i}^{31}

Use indices to rewrite the expression as:

=  {i}^{30}  \times i

We know that

{i}^{2}  =  - 1

So we rewrite the expression to obtain;

=  ({ {i}^{2}) }^{15}  \times i

This gives us;

=   {( - 1) }^{15}  \times i

This simplifies to

=  - 1 \times i

=  - i

4 0
3 years ago
Other questions:
  • The sum of two numbers is 42 and the difference is 20. What are the numbers?
    7·1 answer
  • What decimal is divisible by 55 ?
    5·1 answer
  • 4 times a number cubed decreased by 7... write an algebraic expression
    9·1 answer
  • There are two factors of -36 such that one factor is 11 less than half of the other factor. Choose all the pairs of these factor
    11·1 answer
  • P(x&lt;40)= find the answer
    6·1 answer
  • What is 22 divided by 7?
    11·1 answer
  • Exam
    9·1 answer
  • a number is divided into 2 parts. one part is 10 more than the other, 2parts are in the ratio 5:3 find the number n the 2 parts​
    10·1 answer
  • Helppp i dont understand
    13·1 answer
  • Find the solutions of the quadratic equation –9x2 + 49 = 0.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!