1.In a manufacturing company the job of controlling over the incoming raw materials and the outgoing finished products is usually known as

Quality control

Acceptance sampling

Process control

All of the above

2. Suppose a manufacturing process with a defective rate of 0.03. Which of the following represents the correct interpretations of this probability?

A defective product will never be manufactured.

Three defective product will certainly be manufactured three times out of every 100 products

Three defective products will be expected to be manufactured out of every 100 products

There defective products could be manufactured, or they couldn't be, the chances of either result are the same.

3. Past data has shown that the regression line relating the final exam score (y) and the midterm exam score (x) is presented as:y=50+0.5x

Regarding to the equation above, which of following statement interprets the slope?

A student who gets 50 points from the midterm would be assumed to score 75 points on the final exam.

A student who gets 4 points greater than another student on the midterm would be assumed to get 1 point greater than that student on the final exam.

A student who gets 100 points from the midterm would be assumed to score 100 points on the final exam.

None of the above

4. Which of the following statement is true about the standard deviation (x?) of x? in a sample size n ?

when n increases, x? increases

when n increases, x? decreases

when n increases, x? does not change

x? is an estimation of the standard error of x?

5. Which of the following is a meaningful reason in order to eliminate an outlier from a dataset?

The outlier is the result of natural variability in the measurement of interest.

The outlier clearly belongs to a different population.

The outlier is more than two standard deviations from the mean.

The outlier is the only negative number in the dataset.

6. A sample of 400 metal hardness values selected from a dataset, where the sample is normally distributed with mean 120 and standard deviation 10. According to the given information, which interval is more likely to include over 99% of the metal hardness values in the sample?

119 to 121

110 to 130

100 to 140

90 to 150

7. The following histogram shows the length of a certain person's cell phone calls in minutes for one month. What is the approximate shape of the distribution?

x?

uniform

left-skewed

right-skewed

symmetric

8. For the distribution in question 6, which of the following measures are more appropriate for center and spread?

Mean and standard deviation

Median and interquartile range

Mean and interquartile range

Median and standard deviation

9. If the weights of 30 bags added to the total weight of 80 bags and the total weight is divided by 80, the result equals to 36lbs.Which of the following statement is true corresponding to the result?

It is a statistic so that it shows some characteristic of a sample.

It is a parameter so that it shows some characteristic of a sample.

It is a statistic so that it shows some characteristic of a population.

It is a parameter so that it shows some characteristic of a sample.

10. The average time of a particular manufacturing process has a mean of 66 and a standard deviation of 5 seconds. Suppose that 100 products was manufactured today. Find the probability that the average time of the 100 products exceeded 67 seconds.

0.3707

0.0228

0.4772

0.1293