Statistics Final: Multiple choice and true/false

Identify the outlier of the set of values (55, 57, 40, 47, 39, 38, 72) a. 47 b. 72 c. 38 d. 40

b. 72

A frequency distribution is skewed, when a vertical line can be drawn through the middle of the graph, and the resulting halves are approximately mirror images.

False

A statistical hypothesis is a statement about a sample.

False

An ogive is a graph used for relative frequencies.

False

An outlier is any number less than Q1 or greater than Q3

False

As the size of a sample increases, the standard distribution of the sample means increases.

False

Data at the ordinal level are qualitative only

False

Data at the ratio level cannot be put in order

False

Ha is a statistical hypothesis that contains a statement of equality.

False

In a normal distribution, the mean can be less than the mode and median.

False

The area shown in the Standard Table gives the probability to the right of the z-score.

False

The expected variable of a random variable can never be negative.

False

The first step of designing a statistical study is to develop a plan

False

The probability of event E is 0 < P(E) < 100

False

The range of the values of the correlation coefficient is between 0 and 1.

False

The sum of the central angles of a pie chart is 100 degrees

False

You toss a coin and roll a die. the event "tossing tails and rolling an even number" is a simple event.

False

5! = 120

True

A correlation coefficient of two variable data is represented by the symbol "r".

True

A data set can have the same mean, median, and mode

True

A normal curve is bell shaped and symmetric about the mean.

True

About one quarter of the data falls below Q1

True

Class boundaries ensure that consecutive bars of a histogram touch.

True

For a random variable "x" (in probability distributions) the word "random" indicates the value of "x" is determined by chance.

True

If the size of a sample is at least 30, then you can use the z-scores to determine the probability that a sample mean falls in a given interval of the sampling distribution.

True

In a hypothesis test, you assume that the null hypothesis is true.

True

Of all the measures of central tendency, the mean is the one which is most affected by an outlier

True

The last step in designing a statistical study is identify and possible errors

True

The midpoint of a class is the sum of the lower and upper limits divided by two.

True

The second quartile is the median of the data set

True

The standard deviation of the sample means is also called the standard error of the mean.

True

The total area of under the normal curve is equal to one.

True

Two variables have a negative linear correlation. The dependent variable increases as the independent variable increases.

True

Which of the following probabilities would be considered unusual? a. 0.03 b. 0.13 c. 0.50 d. 0.90

a. 0.03

The table lists the results of a survey of the students at a community college. Suppose a student is selected at random. Find P(female | student takes biology). a. 13/22 b. 116/239 c. 13/29 d. 52/239

a. 13/22

The lengths of a certain species of fish were found to be normally distributed. The mean length is 79 cm with a standard deviation of 10 cm. In a school of 310 of these fish, about how many would be longer than 69 cm? a. 260 fish b. 302 fish c. 42 fish d. 105 fish

a. 260 fish

Find the range and the interquartile range of the set of values. 31, 16, 39, 15, 18, 41, 24, 26, 21, 33, 9, 12 a. range: 32, interquartile range: 16.5 b. range: 32, interquartile range: 18 c. range: 32, interquartile range: 15 d. range: 33, interquartile range: 16.5

a. range: 32, interquartile range: 16.5

The only time we used a t-distribution in Hypothesis testing for the mean was when: a. standard deviation was unknown b. standard deviation was known c. never used d. when p = .5

a. standard deviation was unknown

The table gives data about municipal waste collected and recycled by type. find P( paper | not recycled). a. 65.9% b. 81.7% c. 24.8% d. 33%

b. 81.7%

The "a" in Ha stands for: a. active b. alternative c. area d. analytical

b. alternative

On your Table 5, "t-distribution" d.f stands for degrees of ___, which is ___ your value of "n" a. freedom, one more than b. freedom, one less than c. frequency, one more than d. frequency, one less than

b. freedom, one less than

Find the mean and standard deviation for the set of sample values. 25, 19, 5, 21, 18, 22, 17, 10, 7 a. mean: 18, standard deviation: 6.91 b. mean: 16, standard deviation: 6.62 c. mean: 16, standard deviation: 6.91 d. mean: 18, standard deviation: 6.62

b. mean: 16, standard deviation: 6.62

Make a box and whisker plot for the set of values. 5.2, 9.2, 5.2, 3.2, 3.2, 7.2, 6.2, 8.2, 5.2, 4.2, 5.2, 6.2, 9.2, 9.2, 8.2 a. minimum = 3.2; maximum = 9.3; Q1 = 5.2; Q2 = 6.2; Q3 = 8.3 b. minimum = 3.2; maximum = 9.2; Q1 = 5.2; Q2 = 6.2; Q3 = 8.2 c. minimum = 3.1; maximum = 9.2; Q1 = 5.1; Q2 = 6.7; Q3 = 8.2 d. minimum = 3.2; maximum = 9.4; Q1 = 5.2; Q2 = 6.7; Q3 = 8.2

b. minimum = 3.2; maximum = 9.2; Q1 = 5.2; Q2 = 6.2; Q3 = 8.2

What is the total area under a normal curve? a. 0 b. .5 c. 1 d. answer varies

c. 1

A class of 30 students has 11 honor students and 13 athletes. Three of the honor students are also athletes. One student is chose at random. Find the probability that this student is an athlete if it is known that the student is not an honor student. a. 2/19 = .105 b. 13/30 = .433 c. 10/19 = .526 d. 13/19 = .684

c. 10/19 = .526

Determine the number of standard deviations that includes all data values listed for the situation. The mean time employees take of a company to commute to work is 40.75 minutes; the standard deviation is 12.8 minutes. 42, 45, 53, 34, 12, 48, 52, 24, 56, 47, 28, 48 a. 1 standard deviation b. 2 standard deviations c. 3 standard deviations d. 4 standard deviations

c. 3 standard deviations

Use the frequency table to find P( 2 or 3 children). a. 12% b. 21% c. 42% d. 30%

c. 42%

The heights of 750 students at a local school were recorded and found to be approximated by this normal curve. What could the mean and the standard deviation for these data be? a. 69, 5 b. 65, 8 c. 65, 4 d. 53, 4

c. 65, 4

The number of patients treated at Dr. Holman's dentist office each day was recorded for 7 days. Using the data 3, 10, 18, 9, 22, 20, and 2, find the mean, median, and mode. a. no mean, median: 10, mode: 12 b. mean: 14, median: 12, mode: 10 c. mean: 12, median: 10, no mode d. meanL 10, median: 12, no mode

c. mean: 12, median: 10, no mode

Find the mean, median, and mode of the set of values. 5, 20, 6, 5, 18, 12, 13, 14 a. mean: 13, median: 12, mode: 5 b. mean: 13, median: 12, mode: 13 c. mean: 12, median: 13, mode: 5 d. mean: 12, median: 13, mode: 13

c. mean: 12, median: 13, mode: 5

A "z score" is 0. Which of the following is true? a. the mean is 0 b. the corresponding x-value is 0 c. the corresponding x-value is equal to the mean d. there is no area

c. the corresponding x-value is equal to the mean

Which is not a description of the symbol H0? a. the null hypothesis b. h subzero c. the other hypothesis d. h naught

c. the other hypothesis

Which of the numbers CANNOT express a probability of an event? a. .67 b. 0 c. 17/19 d. 1.09

d. 1.09

Each person in a group of students was identified by hair color and then asked whether he or she preferred taking classes in the morning, afternoon, or evening. The results are in the table. Find the probability that a student preferred morning classes given that he or she has blonde hair. a. 26/53 = .491 b. 4/11 = .364 c. 25/53 = .472 d. 1/3 = .333

d. 1/3 = .333

which of teh following hypothesis claims would produce a "two tailed" test? a. H0 p (less than or equal to) 0.61 b. H0 p (greater than or equal to) 0.61 c. Ha p < 0.61 d. Ha p (not equal to) 0.61

d. Ha p (not equal to) 0.61

Which of the following is not equal in a normal distribution? a. mean b. mode c. median d. area

d. area

Give the complement to p > .6 a. p = .4 b. p (greater than/equal to) .6 c. p < 6 d. p (less than/equal to) .6

d. p (less than/equal to) .6