# Data Management

Topics: Sampling, Standard deviation, Median Pages: 9 (2658 words) Published: April 29, 2013
MDM4U Final Exam REVIEW

**This review is a supplement only. It is to be used as a guide along with other review.

Chapter 1

1. The circle graph shows the relative size of each
grade (9, 10, 11, and 12) in a high school.
(a) If the school has 900 students in all, calculate the
number of students in each grade.
(b) Construct a new circle graph to show how the
percent of Grade 9 students rose by 10% and the
percent of Grade 11 students fell by 10% the
following year. Compare graphs.

2. Analyze the following box-and-whisker plot. What are the median value for the whole sample, the median values for each half, and the range?

3. Students in Mrs. Singh’s math class were asked if they
can watch television and do math homework at the
same time. According to the results shown on the right,
are males or females more likely to think they are able
to do this? Explain. (The darker area represents Males)

4. Dexter is 45 years old and 181 cm tall. For the last 8 years, his doctor has charted Dexter’s mass and related it to his BMI (Body Mass Index). A BMI between 20 and 26 is considered healthy. The data is shown in the following table.

Mass(kg)62 72 66 79 85 82 92 88
BMI 19 22 20 24 26 25 28 27
(a) Create a scatter plot for the data.
(b) Describe any trends in the data. Explain.
(c) Construct a median–median line for the data. Write a question that requires the median– median line to make a prediction.
(d) Determine the equation of the median–median line that you constructed. (e) If Dexter’s mass was 83 kg in the ninth year, what do you predict would be his BMI? (f) In which year(s) was Dexter’s BMI outside of the “healthy zone”? (g) Dexter’s friend Chandra is 167 cm tall. If she had the same mass, how do you think her graph would differ from Dexter’s? Explain.

Chapter 2

1. For each of the scenarios below, (i) determine the population, (ii) create a suitable thesis question, (iii) identify the key variables, (iv) state whether the data is qualitative or quantitative, (v) for the variables that are quantitative, state whether the data will be discrete or continuous, (vi) determine whether a census or sample should be used and describe it, and (vii) state whether a cross-sectional or longitudinal study would be most appropriate to draw conclusions.

(a) A travel company calls people to ask where and how often they take vacations. (b) A child psychologist wants to find out if “skipping” a student ahead to the next grade would hinder her socially.

(c) Clients at a dental office are asked how much they spend on average on dentistry per year.
(d) A shoe store wishes to determine trends in consumer buying habits over the next 10 years.

2. The following is a list of species for five types of animals.

(a) Select 6 animals using simple random sampling.
(b) Select 5 animals using systematic random sampling.
(c) Select 10 animals using stratified random sampling.

3. Identify the type(s) of bias that may result from each of the following data collection methods. (a) You wish to find out how many hours teenagers spend playing video games on an average school night, so you survey your school’s computer club. (b) You wish to determine how many students will come to an upcoming dance and so you send a survey to all Grade 9 classes.

(c) To collect data on teen shopping habits, you send surveys to every third house on a street. (d) You take a random sample of females to survey them about their preference towards various brands of potato chips.

(e) You are interested in determining how many hours of television teenagers in your school watch per week, so you survey the chess club.

4. Give an example of a survey with household bias and another example of one with sampling bias. How do they differ? Explain.

Chapter 3

1. Lulu’s quiz marks were 67, 45, 55, and 60 for the first four days of this week. By the end of Friday, her mean...