In order to determine the effectiveness of a new vaccine that is alleged to cure "math anxiety," a study was conducted. One thousand volunteer college students enrolled in math courses across the U.S. were chosen. The 1000 students were broken up into two groups. Those enrolled in calculus courses were given the real vaccine. The students in developmental (remedial) math courses were given a fake vaccine consisting of sugared water. None of the students knew whether they were being given the real or the fake vaccine, but the researcher conducting the study knew. At the end of the semester the students were given a test that measured their level of math anxiety. The students in the treatment group showed significantly lower levels of math anxiety than those in the control group. On the
basis of this experiment the vaccine was advertised as being highly effective in fighting math anxiety.This study can best be described as a
A. survey using stratified sampling.
B. randomized controlled experiment.
C. survey using quota sampling.
D. controlled placebo experiment.
E. census.
Answer: D
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Solve the problem.The volume V of a given mass of gas varies directly as the temperature T and inversely as the pressure P. 
when 
and P = 10 lb/ in.2, what is the volume when 
and 
A. 290.0 in.3 B. 230.0 in.3 C. 270.0 in.3 D. 240.0 in.3
Provide an appropriate response.Given two linear equations in standard form, how can you determine if the lines are parallel by inspection? Create examples to illustrate your answer.
What will be an ideal response?
Write the ratio as a fraction in lowest terms. Be sure to make all necessary conversions.9
days to 2
weeks
A. 
B. 
C. 
D. 
Find all solutions of the following equation in the interval [0, 2?).
?
?
A. 
B. ?
C. ?
D. ?
E. ?