Mat150-Statistics

Test 1 Review

Prof. Demirel

The test consists of chapters 1-3. Below are topics you should focus on to get ready for the test.

Tell whether descriptive or inferential statistics have been used.

Classify each variable as qualitative or quantitative.

Classify each variable as discrete or continuous.

Given raw data, construct a frequency table with desired classes.

Given a frequency table, determine the class width, class limits, class boundaries, midpoints,

cumulative frequency, relative cumulative frequency.

Draw the histogram, frequency polygon, ogive using the frequency table.

Answer questions using the ogive and the relative frequencies.

Create a pie graph.

Construct a stem and leaf plot and describe the shape of the distribution.

Given a data set, find the mean, median, mode, midrange, variance and standard deviation.

Given two data sets, determine which is more variable.

Given a frequency distribution, find the modal class and the mean. Describe the shape of the

distribution.

Use a weighted mean to calculate the average of a data set.

Given a data set, find and determine if there are any outliers.

Use z-scores to compare relative position.

Review Exercises

1) In each of the statements below, tell whether inferential or descriptive statistics have been used.

a) Economic uncertainty has caused people to travel less.

b) Eating whole grain cereal helps lower the cholesterol level.

c) In the year 2012, the average cost of attending private college will be $49,581.

d) The mean price of a home in Alaska was $144000 in 2000.

2) Classify whether qualitative or quantitative variable is used in the statements below.

a) Flavors of ice cream in an ice cream shop.

b) Number of pair of shoes in a closet.

c) Mascots of Professional basketball teams.

d) Marital status of nurses in a hospital.

3) Classify whether discrete or continuous variable is used in the statements below.

a) Lengths of cash register slips.

b) Number of pizzas sold buy Pizza Hut each day.

c) Number of customers in an ice cream shop.

d) The time it takes to wait in line to pay for your groceries in a store.

4) A study was conducted to determine how people get jobs. The table below lists 400 randomly selected

subjects. Construct a pie graph that corresponds to the given data.

Job Sources of Survey Respondents Frequency

Help-wanted ads 56

Executive search firms 44

Networking 280

Mass mailing 20

5) The fuel capacity in gallons of 50 randomly selected cars is shown here.

Class Frequency

10-12 6

13-15 4

16-18 14

19-21 15

22-24 8

25-27 2

28-30 1

Find the following.

a) Boundaries

b) The class width

c) The upper limit of the 5th class

d) The lower limit of the 2nd class

e) Midpoints

6) Use the frequency table in number 5 to create a histogram, frequency polygon and an ogive.

a) What percent of the cars have a fuel capacity less than 21?

b) What percent of the cars have a fuel capacity greater than 26?

c) What is the fuel capacity of 50% of cars or less?

7) The data shown are the number of grams per serving of 30 selected brands of cakes. Construct a

frequency distribution using 5 classes.

32 47 51 41 46 30 25 29 33 45 51 32

46 38 34 34 52 48 32 27 23 23 34 35

48 38 43 41 21 24

8) The following data represents the ages (in years) of the best actresses in academy awards. Construct a

stem and leaf plot and analyze the data.

57 54 52 55 51 56

61 68 56 55 54 61

57 51 46 54 51 52

57 49 54 42 60 69

58 64 49 51 62 64

57 48 51 56 43 46

61 65 47 55 55 54

47 51

9) Researchers at the University of Maryland collected body temperature readings from a sample of

adults, and eight of those temperatures are listed below (in degrees of Fahrenheit).

98.6 98.6 98.0 98.0

99.0 98.4 98.4 98.4

Find the following.

a) Mean

b) Mode

c) Median

d) Midrange

e) Range

f) Variance

g) Standard Deviation

10) Using the weighted mean, find the average number of grams of fat per ounce of meat or fish that a

person would consume over a 5-day period if he ate these:

Meat or fish Fat (g/oz)

3 oz fried shrimp 3.33

3 oz veal cutlet (broiled) 3.00

2 oz roast beef (lean) 2.50

2.5 oz fried chicken drumstick 4.40

4 oz tuna (canned in oil) 1.75

11) The average number of days construction workers miss per year is 11. The standard deviation is 2.3.

The average number of days factory workers miss per year is 8 with a standard deviation of 1.8.

Which class is more variable in terms of days missed?

12) The data below represents the values in billions of dollars of the damage in 10 hurricanes.

1.1 1.7 1.9 2.1 2.2

2.5 3.3 6.2 6.8 20.3

a) Find the percentile rank for 3.3.

b) What value corresponds to the 40th percentile?

13) Use the data set given below to determine

a)

b)

c)

d)

e) Would you consider 90 an outlier?

f) Is 101 and outlier?

14) A student graduated from a 4-year college with an outstanding loan of $9650 where the average debt

is $8455 with a standard deviation of $1865. Another student graduated from a university with an

outstanding loan of $12,360 where the average of the outstanding loans was $10,326 with a standard

deviation of $2143. Which student had a higher debt in relationship to his or her peers?