Statistic exam | Mathematics homework help

1. The portion of the universe that has been selected for analysis is called:

Question 2

One of the advantages of a pie chart is that it clearly shows that the total of all the categories of the pie adds to 100%.

Answer

True

False

Question 3

Which of the 4 methods of data collection is involved when a person counts the number of cars passing designated location on the Los Angeles freeway system?

Question 4

The coefficient of variation is a measure of the central tendency in the data.
Answer

True

False

Question 5

Which of the following is NOT a measure of central tendency?

Question 6

A Pareto diagram is a bar chart in which the bars are naturally arranged with a decreasing pattern:

Answer

True

False

-Question 7

If two events are collectively exhaustive, what is the probabiltiy that one or the other occurs?

Question 8

The cross-tabulation of two categorical variables leads to a contingency table:

Answer

True

False

Question 9

A business venture can result in the following outcomes (with their corresponding chance of occuring in parenthesis); Highly Successful (10%), Successful (25%), Break Even (25%), Disappointing (20%), and Highly Disappointing (?). If these are the only outcomes possible for the business venture, what is the chance that the business venture will be considered Highly Disappointing?

4 points

Question 10

A population consists of all the possible objects to be studied:

Answer

True

False

4 points

Question 11

An economics professor bases his final grade on homework, two midterm examinations, and a final examination. The homework counts 10% toward the final grade, while each midterm counts 25%. The remaining porttion consists of the final exam. If a student scored 95% in homework, 70% on the first midterm, 96% on the second midterm, and 72% on the final exam, his final average is 79.8%

Answer

True

False

4 points

Question 12

If event A and Event B cannot occur at the same point in time, then events A and B are said to be

4 points

Question 13

Thirty-six of the staff of 80 teachers at a local intermediate school are certified in Cardio-Pulmonary Resuscitation (CPR). In 180 days of school, about how many days can we expect that the teacher on bus duty will likely be certified in CPR

4 points

Question 14

If we randomly draw a ball from a bag with a finite number of balls in it, then put the ball back into the bag and randomly draw another ball from the bag, this is an example of sampling with replacement

Answer

True

False

4 points

Question 15

The Standard Normal distribution has a mean of 1 and a standard deviation of 1.

Answer

True

False

4 points

Question 16

Marginal probability is also called

4 points

Question 17

If n = 10 and p = 0.70, then the standard deviation of the binomial distribution is

4 points

Question 18

In its standardized form, the normal distribution

4 points

Question 19

The “empirical rule” for the bell-shaped curve states that the percentage of data points falling within three standard deviations away from the mean is 99.7%

Answer

True

False

4 points

Question 20

Distribution 1 is a skewed distribution and Distribution 2 is a symmetric distribution (not Normal distribution). Similar sample sizes will be required for the sample mean of random samples from the two distributions to have an approximate Normal distribution.

Answer

True

False

4 points

Question 21

The null hypothesis Ho always contains an equal sign

Answer

True

False

4 points

Question 22

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 3 minutes.

4 points

Question 23

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the point in the distiribution that 75.8% of the college students exceed when trying to find a parking spot in the library parling lot.

Answer

4 points

Question 24

The fact that the sample means are less variable than the population data can be observed form the standard error of the mean.

Answer

True

False

4 points

Question 25

In left-skewed distribution, the median is