INTRODUCTION TO STATISTICS SOPHIA PATHWAYS
Introduction to Statistics Sophia Pathways
Unit 1 Milestone 1 Key Principles of Statistical Methods
You passed this Milestone
29 questions were answered correctly.
1
Jenae noticed that many of her co-workers would opt for the coffee that
appeared to be most recently brewed, regardless of the flavor of the coffee
offered. This leads her to believe that what she was witnessing was not really
representative of everyone's true flavor preferences. She adapted her
experimental study accordingly.
Select one control in Jenae's experimental study.
Jenae keeps the same amount of sugar and artificial sweetener at each location.
Jenae takes note of the frequency in which co-workers refill their coffee mugs.
Jenae monitors the habits of the co-workers who do not drink coffee.
Jenae places condiments at random places throughout the kitchen.
RATIONALE
In an experiment, controls are when conditions are manipulated by the experimenter to
keep them constant. If she keeps the same amount of sweetener at all locations, this
would be an example of a control.
CONCEPT
Experimental Design
2
Jay wants to study nutrition and performance in schools using available data.
Which of the scenarios below will provide Jay with available data?
, Going to a local high school and asking the principal for information about
students' current and previous grades, then interviewing a random selection of
students about their eating habits.
Going to a local college and asking current undergraduates to report their grades
and eating habits from high school.
Going to a local high school and asking the principal for information about
students' previous grades, then interviewing a random selection of students
about their eating habits.
Going to a local high school and asking the principal for information about
students' current and previous grades, then asking the health teacher for the
results from a survey students took in health class.
RATIONALE
Recall, for data to be considered available data it must already be collected. Since the
grades data and survey data were already collected these are examples of available
data.
CONCEPT
Data
3
At a school of 900 students, 20% have blue eyes. A student randomly selects
100 students and finds 17% of them have blue eyes. A second student takes
another random sample of 90 students and finds 24% of them have blue
eyes.
Which of the following explains why there is a difference between
the two percentages?
The sample sizes were both too small.
The samples were not random samples.
Random error; the numbers were different due to variability inherent in sampling.
, Both samples suffered from non-response bias.
RATIONALE
When sampling, there is always some variability that occurs. So,
although the sample values are different and not equal to the true overall proportion of
20%, since they were randomly chosen, the differences are simply due to the variability
that comes from sampling and not due to some systematic bias. As the sample size
increases we would expect these differences to get smaller.
CONCEPT
Random and Systematic Errors
4
Which of these random samples represents a representative sample
of the number of students in a middle school who walk to school?
5 students in the hallway
All students in chess club
150 random students at lunch
25 random 8th graders
RATIONALE
For a sample to be representative it needs to look like the entire set of interest. So, a
random sample of all students at lunch will best represent the student population of
interest.
CONCEPT
Random & Probability Sampling
5
Researchers want to study the effects of classical music and memory. One
group of participants will take a memory test with classical music playing in
the background, while the other group will take the memory test in complete
silence. It is believed that age has an effect on memory.
Which of the following would work best to test if classical music has
an effect on memory?
Introduction to Statistics Sophia Pathways
Unit 1 Milestone 1 Key Principles of Statistical Methods
You passed this Milestone
29 questions were answered correctly.
1
Jenae noticed that many of her co-workers would opt for the coffee that
appeared to be most recently brewed, regardless of the flavor of the coffee
offered. This leads her to believe that what she was witnessing was not really
representative of everyone's true flavor preferences. She adapted her
experimental study accordingly.
Select one control in Jenae's experimental study.
Jenae keeps the same amount of sugar and artificial sweetener at each location.
Jenae takes note of the frequency in which co-workers refill their coffee mugs.
Jenae monitors the habits of the co-workers who do not drink coffee.
Jenae places condiments at random places throughout the kitchen.
RATIONALE
In an experiment, controls are when conditions are manipulated by the experimenter to
keep them constant. If she keeps the same amount of sweetener at all locations, this
would be an example of a control.
CONCEPT
Experimental Design
2
Jay wants to study nutrition and performance in schools using available data.
Which of the scenarios below will provide Jay with available data?
, Going to a local high school and asking the principal for information about
students' current and previous grades, then interviewing a random selection of
students about their eating habits.
Going to a local college and asking current undergraduates to report their grades
and eating habits from high school.
Going to a local high school and asking the principal for information about
students' previous grades, then interviewing a random selection of students
about their eating habits.
Going to a local high school and asking the principal for information about
students' current and previous grades, then asking the health teacher for the
results from a survey students took in health class.
RATIONALE
Recall, for data to be considered available data it must already be collected. Since the
grades data and survey data were already collected these are examples of available
data.
CONCEPT
Data
3
At a school of 900 students, 20% have blue eyes. A student randomly selects
100 students and finds 17% of them have blue eyes. A second student takes
another random sample of 90 students and finds 24% of them have blue
eyes.
Which of the following explains why there is a difference between
the two percentages?
The sample sizes were both too small.
The samples were not random samples.
Random error; the numbers were different due to variability inherent in sampling.
, Both samples suffered from non-response bias.
RATIONALE
When sampling, there is always some variability that occurs. So,
although the sample values are different and not equal to the true overall proportion of
20%, since they were randomly chosen, the differences are simply due to the variability
that comes from sampling and not due to some systematic bias. As the sample size
increases we would expect these differences to get smaller.
CONCEPT
Random and Systematic Errors
4
Which of these random samples represents a representative sample
of the number of students in a middle school who walk to school?
5 students in the hallway
All students in chess club
150 random students at lunch
25 random 8th graders
RATIONALE
For a sample to be representative it needs to look like the entire set of interest. So, a
random sample of all students at lunch will best represent the student population of
interest.
CONCEPT
Random & Probability Sampling
5
Researchers want to study the effects of classical music and memory. One
group of participants will take a memory test with classical music playing in
the background, while the other group will take the memory test in complete
silence. It is believed that age has an effect on memory.
Which of the following would work best to test if classical music has
an effect on memory?
