10/10/2020 Assignment 4 - Inference for categorical variables
Assignment 4 - Inference for
categorical variables
Click on a question number to see how your answers were marked and, where
available, full solutions.
Question Number Score
Question 1 23 / 28
Question 2 5 / 11
Question 3 4 / 12
Question 4 18 / 18
Total 50 / 69 (72%)
Performance Summary
Exam Name: Assignment 4 - Inference for categorical variables
Session ID: 01440799835
Student's Name: K (Katarina) Djordjevic (011cdd57506642ec949f60ac53aa58da)
Exam Start: Sat Oct 10 2020 09:23:30
Exam Stop: Sat Oct 10 2020 10:06:21
Time Spent: 0:42:50
Question 1
We are interested in estimating the proportion of graduates at a mid-sized university who
found a job within one year of completing their undergraduate degree. Suppose we conduct
a survey on current graduate students, and find out that 154 of 226 randomly sampled
graduate students found jobs. The graduate class under consideration included over
13568 students. Answer the following questions, and where applicable and unless otherwise
stated, round and give your answers to two decimal places.
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 1/16
,10/10/2020 Assignment 4 - Inference for categorical variables
a)
What is the value of the point estimate of this parameter?
Expected answer: 0.68
0.68
Your answer is correct. You were awarded 2 marks.
You scored 2 marks for this part.
Score: 2/2
b)
What is the population parameter of interest?
The number of students sampled who found a job.
The number of students to use in the sample.
The true proportion of graduate students at the university who found a job.
The true number of graduate students at the university who found a job.
All students at the university.
The proportion of students sampled who found a job.
You chose a correct answer. You were awarded 1 mark.
You scored 1 mark for this part.
Score: 1/1
c)
Which of the following conditions, or part of a condition, for constructing a confidence
interval based on these data are met? Select all (4) correct options, but note that
incorrect options selected are negatively marked.
The graduate students in the sample are independent of each other.
h d f h
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 l d h f d j b 2/16
, 10/10/2020 Assignment 4 - Inference for categorical variables
More than 10 students from the sample group are expected to have found a job.
The sampled graduate students are not independent of all the graduate
students.
Less than 10% of graduate students did not find a job.
More than 10 graduate students were included in the sample.
The sample included more graduate students who found a job than those who
did not.
More than 10 students from the sample group did find a job.
Less than 10% of all graduate students at the university who did not find a job
were included in the sample.
Less than 10% of all graduate students at the univeristy were included in the
sample.
More than 10 students from the sample group did not find a job.
More than 10% of graduate students did find a job.
You chose a correct answer. You were awarded 1 mark.
You chose a correct answer. You were awarded 1 mark.
You chose a correct answer. You were awarded 1 mark.
You scored 3 marks for this part.
Score: 3/4
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 3/16
Assignment 4 - Inference for
categorical variables
Click on a question number to see how your answers were marked and, where
available, full solutions.
Question Number Score
Question 1 23 / 28
Question 2 5 / 11
Question 3 4 / 12
Question 4 18 / 18
Total 50 / 69 (72%)
Performance Summary
Exam Name: Assignment 4 - Inference for categorical variables
Session ID: 01440799835
Student's Name: K (Katarina) Djordjevic (011cdd57506642ec949f60ac53aa58da)
Exam Start: Sat Oct 10 2020 09:23:30
Exam Stop: Sat Oct 10 2020 10:06:21
Time Spent: 0:42:50
Question 1
We are interested in estimating the proportion of graduates at a mid-sized university who
found a job within one year of completing their undergraduate degree. Suppose we conduct
a survey on current graduate students, and find out that 154 of 226 randomly sampled
graduate students found jobs. The graduate class under consideration included over
13568 students. Answer the following questions, and where applicable and unless otherwise
stated, round and give your answers to two decimal places.
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 1/16
,10/10/2020 Assignment 4 - Inference for categorical variables
a)
What is the value of the point estimate of this parameter?
Expected answer: 0.68
0.68
Your answer is correct. You were awarded 2 marks.
You scored 2 marks for this part.
Score: 2/2
b)
What is the population parameter of interest?
The number of students sampled who found a job.
The number of students to use in the sample.
The true proportion of graduate students at the university who found a job.
The true number of graduate students at the university who found a job.
All students at the university.
The proportion of students sampled who found a job.
You chose a correct answer. You were awarded 1 mark.
You scored 1 mark for this part.
Score: 1/1
c)
Which of the following conditions, or part of a condition, for constructing a confidence
interval based on these data are met? Select all (4) correct options, but note that
incorrect options selected are negatively marked.
The graduate students in the sample are independent of each other.
h d f h
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 l d h f d j b 2/16
, 10/10/2020 Assignment 4 - Inference for categorical variables
More than 10 students from the sample group are expected to have found a job.
The sampled graduate students are not independent of all the graduate
students.
Less than 10% of graduate students did not find a job.
More than 10 graduate students were included in the sample.
The sample included more graduate students who found a job than those who
did not.
More than 10 students from the sample group did find a job.
Less than 10% of all graduate students at the university who did not find a job
were included in the sample.
Less than 10% of all graduate students at the univeristy were included in the
sample.
More than 10 students from the sample group did not find a job.
More than 10% of graduate students did find a job.
You chose a correct answer. You were awarded 1 mark.
You chose a correct answer. You were awarded 1 mark.
You chose a correct answer. You were awarded 1 mark.
You scored 3 marks for this part.
Score: 3/4
https://numbas.up.ac.za/run_attempt/85020?resource_link_id=_2035663_1 3/16
