A drug company wanted to test a new depression medication. The researchers found 400 adults aged 25-35 and randomly assigned them to two groups. The first group received the new drug, while the second received a placebo.
After one month of treatment, the percentage of each group whose depression symptoms decreased was recorded and compared. What is the response variable in this experiment?
A) the 400 adults aged 25-35
B) the type of drug (medication or placebo)
C) the one month treatment time
D) the percentage who had decreased depression symptoms
Q. 2z = -0.3 and z = 0.3
A) 0.5 B) 0.2358 C) 0.6179 D) 0.3821
Q. 3A report on the nightly news broadcast stated that 11 out of 127 households with pet dogs were burglarized and 22 out of 200 without pet dogs were burglarized.
A) z = -0.684 B) z = -0.274 C) z = -0.001 D) z = -1.163
Q. 4A variable is normally distributed. 42 of the possible observations of the variable lie between 20 and 28. What information does this give you about the graph of the normal curve for this variable?
What will be an ideal response?
Q. 5When 253 college students are randomly selected and surveyed, it is found that 128 own a car. Find a 99 confidence interval for the proportion of all college students who own a car.
A) 0.425 to 0.586 B) 0.455 to 0.557 C) 0.433 to 0.578 D) 0.445 to 0.567
Q. 6Commuting times for employees of a local company have a mean of 63.6 minutes and a standard deviation of 2.5 minutes. What does Chebyshev's Theorem say about the percentage of employees with commuting times between 56.1 minutes and 71.1 minutes?
What will be an ideal response?