Question

1. Defective switches can cause fires in the homes where they are used. A large switch manufacturer takes a Simple Random Sample of 200 switches from all the switches shipped in one day. The laboratory reports that 9 of these were defective. Unknown to the manufacturer, 0.1% (one-tenth of one percent) of all shipped were defective. In this situation,

A) 0.1% is a parameter and 9/200 is a statistic.

B) 9/200 is a parameter and 0.1% is a statistic.

C) both 0.1% and 9/200 are parameters.

D) both 0.1% and 9/200 are statistics.

E) 0.1% is an estimate and 9/200 is a margin of error.

2. A November 2014 poll of 819 adults found that 481 are satisfied with the total cost they pay for their health care. What is the value of the sample proportion p̂who say they are satisfied with the total cost they pay for their health care? (Round your answer to the nearest whole number.)

A) 82%

B) 48%

C) 52%

D) 59%

E) none of these is correct

3.  Researchers studied the effects of prenatal vitamins given to expecting mothers in relation to the health of their babies as they are born. From a volunteer group of 346 pregnant women half were randomly assigned and given vitamins and half were given a placebo. When the babies were born they were given an overall health score (from 1 to 10) and the groups were compared. Which of the following is true?

A) This is an observational study and participants were volunteers

B) This is an experiment and participants were randomly assigned treatments

C) This is an observational study and participants were selected at random

D) This is an experiment but participants selected for themselves a treatment

Answer 1

1. sample size = 200 no.of defects in sample =9

sample proportion of defects = 9/200= statistic

Population proportion of defects= 0.1% = parameter

So the answer is A

2. No.of adults in the poll sample size = n= 819

No.of adults satisfied with the total cost they paid for their health care= x= 481

sample prortion of adults satisfied with the total cost they pay for their health care= x/n=481/819= 0.5873 = 59% approximately

So Answer for the question 2 is D

3.Ans is B) This is an experiment and participants were randomly assigned treatments