Statistics

Question 1

A set of all possible data values for a subject under consideration is called ___.

a) descriptive statistics

b) a sample

c) a population

d) inferential statistics

Question 2

Which of the following can be classified as Discrete and Quantitative data.

a) The acceleration of your car as you drive to school

b) The different colors of the eyes of your classmates

c) The number of students in your school

d) The height of all the people in your neighborhood

Question 3

Can a frequency distribution have overlapping classes?

a) sometimes

b) No

c) Yes

d) Can’t determine I need more information

Question 4

For a 10 point quiz, the professor recorded the following scores for 8 students:

7, 8, 3, 9, 10, 6, 8, 5

What is the Mean for this set of scores?

a) 7.0

b) 6.9

c) 7.5

d) 8.0

Question 5

What type of distribution is described by the following information?

Mean = 56 Median = 58.1 Mode = 63

a) (left) negatively skewed

b) Symmetrical (normal)

c) Bimodal

d) Right (positively) skewed

Question 6

In a standardized IQ test, the mean score is 100 and the standard deviation is 15. According to the Empirical rule, 95 % of all those who took

the test should have scores between

a) 70 & 130

b) 85 & 115

c) 55 & 145

d) 100 & 130

Question 7

A Statistics teacher has the following test scores : 93, 72, 80, 95, 90, 70, 91, 85, 86, 100 What is the median test score of these grades?

a) 90

b) 88

c) 95d) 80

Question 8

There are 10 colored balls in a box ( 5 red, 3 blue, 2 green ). What is the probability of picking out a red ball and then a blue ball ( If I do

not replace the red ball )?

a) 1/6

b) ½

c) 3/20

d) 4/5

Question 9

Given the following scatter diagram, the sample correlation coefficient r:

a) Has a positive linear correlation

b) Has a negative linear correlation

c) Has a title or no correlation

d) Looks close to + 1.00

Question 10

If I go into an ice cream parlor, and I have the choice of having one of 10 different flavors, with one of 5 different toppings and one of 3

different types of cones, How many times can I come back to this place and get a different ice cream cone combination?

a) 10

b) 50

c) 150

d) 300

Question 11

The Sarasota Police department collected data on the number of car accidents ( X ) that occur each day on a certain stretch of route 41. From

this data, they derived the probability distribution shown in the table below.

X P(X)

0 0.80

1 0.15

2 0.05

What is the expected mean (average) number of accidents that occur each day?

a) 0.50

b) 0.25

c) 0.33

d) 1.00

Question 12

The area under a normal curve distribution is

a) Equal to 100

b) Almost equal to 100

c) Equal to 1

d) Equal to 5

Question 13

According to the Central Limit Theorem, The traditional sample size that separates a large sample size from a small sample size is one that is

greater than

a) 100

b) 30

c) 500

d) 20

Question 14

What is meant by the 95% confidence interval of the mean?

a) That 95% of my sample is OK to do more tests

b) That I am 95% confident that the confidence interval will contain the parameter being estimated.

c) That 5% of my sample is not OK

d) That I am 95% sure that the population mean is 95.

Question 15

As the sample size increases

a) The confidence interval also increases (gets larger)

b) The confidence interval decreases (gets smaller)

c) The confidence interval stays the same

d) The population mean increases

Question 16

Consider a binomial random variable where the number of trials is 12 and the probability of success on each trial is 0.25. Find the mean and

standard deviation of this random variable

a) Means = 3, Standard Deviation = 1.5

b) Mean = 4, Standard Deviation = 2.25

c) Mean = 6, Standard Deviation = 2.25

d) Mean = 9, Standard Deviation = 1.5

Question 17

A Type I error means

a) That I accepted the null hypothesis, when it is really false

b) That I rejected the null hypothesis, when it is really true

c) That I didn’t have a large enough sample to make a decision

d) That my positive hypothesis is correct

Question 18

The t distribution should be used when ___.

a) The sampling population is not normal

b) The sampling population is unimodal

c) The sampling distribution is normal and the population standard deviation is unknown

d) The population standard deviation is known.

Question 19

If my p-value = .322 and my significant level is .05 , then

a) My Null Hypothesis is rejected and I must accept the Alternative hypothesis

b) My Null Hypothesis is not rejected

c) My Alternative hypothesis becomes the new Null Hypothesis

d) I cannot make a decision until I know my sample size

Question 20

Suppose I am using the t-distribution to estimate

a) 26

b) 25

c) 24d) 30