<h2>D. If subjects knew they were receiving an active treatment, researchers would not have known if any improvement was due to the new medication or to the expectation of <u>feeling </u>better. If the researchers knew which subjects received which treatments, they might have treated one group of subjects differently from the other group.</h2><h2 />
For your question... the answer would be D
Answer:
A recent report estimated that 25% of all college students in the United States have a sexually transmitted disease (STD). The director of the campus health center believes that the proportion of students with STDs is higher at their campus.
According to the American Heart Association guidelines, the daily maximum amount of sugar a teenager should have is 4 teaspoons. The parents of a local high school have expressed concerns that the average daily sugar intake of their students is higher than these guidelines and have been pressuring school officials to limit unhealthy snack and beverage choices offered in the cafeteria and student store.
Step-by-step explanation:
The first two researches involve the single sample compared to mean of population.
The 3rd and 4th research involves comparing samples of men and women that is two individual groups.
28.23 is the volume of something if the diameter is 2 cm and the height is 9 cm.
Answer:
Null hypothesis = 
Alternate hypothesis =
Step-by-step explanation:
Given : In a recent semester, the proportion who earned a bachelor's degree within six years was 0.395.
The president of a certain college believes that the proportion of students who enroll in her institution have a higher completion rate.
To Find : Determine the null and alternative hypotheses.
Solution:
In a recent semester, the proportion who earned a bachelor's degree within six years was<u> 0.395. </u>
Claim : the proportion of students who enroll in her institution <u>have a higher completion rate.</u>
So,null hypothesis = 
Alternate hypothesis =
Answer:

Step-by-step explanation:
The diagram for the question is attached below
perimeter of the triangle is 28 feet
area of a square is 144 feet
Area of the square is side^2

take square root on both sides
side = 12
side of the square = 12
side is the diameter of the semicircle
Diameter = 12 , so radius = 12 divide 2 = 6
circumference of semicircle = 
one side of the rectangle is calculated in the perimeter of triangle and other side is calculated using circumference
perimeter of other two side = 2(12)= 24
Total perimeter = 