![shontelsims](/avatars/19263.jpg)
shontelsims
04.12.2020 •
Mathematics
A new cream was developed to reduce the irritation caused by poison ivy. To test the effectiveness, researchers placed an ad online asking for 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 activities, and 42 of the subjects state they spend more than 50% of their day outside. 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.
Which of the following describes a randomized block design?
A. The subjects are grouped based on their outdoor activity. The 42 subjects are randomly assigned to the two treatment groups. The remaining 58 subjects are also randomly assigned to the two treatment groups.
B. The subjects are numbered 1–100, and these numbers are entered into a random number generator. Fifty numbers, ignoring repeats, are generated and these subjects receive the new cream. The remaining 50 receive the inactive cream.
C. The subjects are paired based on similar age. Two marbles, one red and one blue, are placed in a bag and mixed. If the first subject picks a red marble, then that subject will receive the new cream and the other subject will receive the inactive cream. If it is blue, then the opposite will occur. This is done for all 50 pairs.
D. The subjects are grouped based on their outdoor activity. The researchers flip a coin and if it lands on heads, then the group with the most sun exposure will receive the new cream and the other group will receive the inactive cream. If the coin lands on tails, then the group with the most sun exposure will receive the inactive cream and the other group will receive the new cream.
Solved
Show answers
More tips
- H Health and Medicine Liver Cleansing - Rejuvenation for the Body?...
- L Leisure and Entertainment Scrapbooking: What is it and Why is it Becoming More Popular?...
- H Horoscopes, Magic, Divination How to Cast a Love Spell on a Guy? Guide for Guys...
- F Family and Home How to Sew Curtain Tapes: Best Tips from Professionals...
- S Style and Beauty How are artificial nails removed?...
- S Style and Beauty How to Make Your Lips Fuller? Ideas and Tips for Beautiful Lips...
- F Food and Cooking The Disease That Haunted Abraham Lincoln...
- C Computers and Internet How to Get Rid of Windows Genuine Check?...
- H Health and Medicine How to perform artificial respiration?...
- S Style and Beauty Tricks and Tips: How to Get Rid of Freckles...
Answers on questions: Mathematics
- M Mathematics Noel and Casey both start at the same place. Noel walks due south and Casey walks due east. After some time has passed, Noel is 6 miles south and Casey is 8 miles east. At this time,...
- M Mathematics The ex coordinateOf an ordered pair is more than half the value of its corresponding why coordinate if the x-coordinate of the order part is 10 what is the largest whole number value...
- M Mathematics Hello can anyone solve this for me.. I want little explanation also.. I am getting stuck on this one... the blue circled can you solve that for me.. the question is: Smita gets 94...
- M Mathematics TIME REMAINING 01:55:49 Which is the graph of f(x) = x2 - 2x + 3? 2 2 3 Mark this and retum Save and Exit Next Submit...
- M Mathematics What are the coordinates of B’ if the figure is reflected across the x-axis? What is the mapping rule for finding the coordinates of a figure reflecting across A) the x-axis (x,y)...
- M Mathematics Por favor ayúdenme a realizar estas operaciones mediante la forma cuadrática. x²+3x+2=0 4(4x-3) = (x+5)(x-5)...
- M Mathematics -5x=25 how to solve this problem ...
- M Mathematics Another one ahahaha please help...
- M Mathematics Select the correct answer from each drop-down menu. Triangle XYZ,,with vertices X(-2, 0), 7(-2,-1), and Z(-5, -2), undergoes a transformation to form triangle X YZ , with vertices...
- M Mathematics If x = -7 and y = 2, what is Vy - 14x?...
Ответ:
C.
Step-by-step explanation:
It shouldn't matter what age they are, this experiment is based on effectiveness and exposure to sunlight. You could be 69 and have more sun exposure than a 29 year old.
Ответ:
Total marbles: 1+ 4+3 = 8
Picking a blue marble = 4/8 = 1/2
Picking a second one: 1/2 x 1/2 = 1/4 probability