Identify the following as an experiment or an observational study.A researcher obtained a random sample of smokers aged between 60 and 70 and a random sample of nonsmokers aged between 60 and 70. She compared the rates of arthritis for the smokers and for the nonsmokers.
A. Experiment
B. Observational study
Answer: B
Mathematics
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Find the value of the specified finite sum.Given 
= -4 and 
= 10, find 
.
A. 40 B. 14 C. -14 D. -16
Mathematics
Solve and check.5z + 11 = 4z + 6
A. z = -17 B. z = 17 C. z = 5 D. z = -5
Mathematics
Solve the equation.6x - 3 - 5x - 12 = 21
A. -12 B. -36 C. 36 D. 12
Mathematics
Solve the problem.Suppose your job is to take phone orders for machine parts. Use the table below to answer the following questions. Write the correct part number that matches what you hear the customer say on the phone. 
"Do you have that part in 1 and 9 tenths centimeters?"
A. G B. A C. F D. D
Mathematics