Collecting Data

Name:

Class:

Date:

Show your work for each problem.

1.
Which of the following is a method of collecting data?
1. a)Survey
2. b)Addition
3. c)Calculation
4. d)Division
2.
The entire group you want to learn about is called the:
1. a)Sample
2. b)Survey
3. c)Variable
4. d)Population
3.
A scientist watches birds at a feeder every morning for a week. This is an example of:
1. a)Observation
2. b)Census
3. c)Experiment
4. d)Survey
4.
A school has 800 students. A researcher surveys 80 students. What percentage of the population is in the sample?
5.
In a survey, 35 out of 100 people preferred option A. What percentage preferred option A?
6.
A student surveys only her friends about their favorite subject. This is an example of:
1. a)Random sampling
2. b)Bias due to convenience sampling
3. c)Observation
4. d)Good experimental design
7.
Which question is biased?
1. a)Don't you think we need more homework?
2. b)How often do you complete homework on time?
3. c)What is your opinion about homework?
4. d)How many hours do you spend on homework?
8.
A company surveys 500 customers. 175 prefer product A, 225 prefer product B, and the rest have no preference. How many customers have no preference?
9.
A researcher surveys 200 people about their favorite season. Spring: 42, Summer: 68, Fall: 54, Winter: 36. What percentage chose summer?
10.
A scientist tests a plant fertilizer. Group A (with fertilizer): average height 24 cm. Group B (no fertilizer): average height 18 cm. How much taller is Group A on average?
11.
Which sampling method would give the LEAST biased results for a school survey?
1. a)Survey the debate club
2. b)Ask students who stay after school
3. c)Randomly select students from the entire school list
4. d)Ask students in the cafeteria at lunch
12.
In a clinical trial, Group A (treatment, 150 people): 108 improved. Group B (placebo, 150 people): 75 improved. What is the difference in improvement rates between the groups?
13.
A town wants to know if residents support a new park. They survey everyone who attends the town hall meeting. What is wrong with this approach?
1. a)Surveys should only be done online
2. b)The sample is too large
3. c)Only people interested in local issues attend, creating selection bias
4. d)Town hall meetings are the best place for surveys
14.
A school with 1200 students wants to survey them about lunch options. They decide to survey 60 students. From each grade (9-12), they randomly select 15 students. What percentage of each grade is in the sample?
15.
A researcher needs a margin of error of about 5%. The general rule suggests a sample of at least 400 for this. If she has 10000 people in her population, what percentage would she need to sample?
16.
An experiment tests two teaching methods. Method A (25 students): test scores 72, 85, 91, 68, 79, mean = 79. Method B (25 students): test scores 88, 76, 92, 84, 80, mean = 84. By how many points did Method B outperform Method A on average?