1) A market survey was conducted to estimate the proportion of homemakers who could recognize the brand name of a cleanser based on the shape and colour of the container. Of the 1,400 homemakers, 420 were able to identify the brand name. Using the 99 percent confidence, the population proportion lies within what interval? (Select the best answer).

Group of answer choices

0.357 and 0.385

0.250 and 0.350

0.950 and 0.997

0.397 and 0.421

0.268 and 0.332

2)Suppose random variable X follows a normal distribution with mean 10. If 16% of observations from this distribution are negative, the coefficient of variation of X is closest to

Group of answer choices

10

0.64

0.32

1

5

3) A university dean is interested in determining the proportion of students who receive some sort of financial aid. Based on a large random sample, the 95% confidence interval for the proportion of students who receive some sort of financial aid is found as (0.52, 0.66). Which one of the following is the best interpretation of this interval?

Group of answer choices

We are 95% confident that between 52% and 66% of the sampled students receive some sort of final aid

We are 95% confident that the true proportion of all students receiving financial aid is between 0.52 and 0.66.

We are 95% confident that 59% of the students are on some sort of financial aid.

95% of the students get between 52% and 66% of their tuition paid for by financial aid.

95% of the students receive some sort of financial aid.

4) The number of auto parts that a company produces follows a normal distribution. The company has two independent production lines: Line 1 produces an average of 75 parts per day with a standard deviation of 20. Line 2 produces an average of 65 parts per day with a standard deviation of 21. Line 1 and Line 2 are independent.

What is the probability that the average number of parts produced by Line 1 is greater than that produced by Line 2 in the next 5 days?

Group of answer choices

0.7794

0.1587

0.6331

0.3413

0.5