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Illowsky and Dean - Collaborative Statistics 2/e (Homework)

James Finch

Statistics, section 2, Fall 2019

Instructor: Dr. Friendly

Current Score : 19 / 130

Due : Sunday, January 27, 2030 23:30 EST

Last Saved : n/a Saving...  ()

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Question
Points
1 2 3 4 5 6 7 8 9 10 11
3/3 3/3 –/3 4/4 9/9 –/9 –/12 –/10 –/10 –/1 –/66
Total
19/130 (14.6%)

  • Instructions

    Collaborative Statistics 2/e, by Barbara Illowsky and Susan Dean, is an open source introductory statistics text available from both Connexions and Orange Grove Open Source Content Repositories. The text offers applications of all the basic tests solved by statistical calculators or software. It is intended for a course requiring just Intermediate Algebra, not Calculus, as a prerequisite.

    Questions include items from the end of chapter Homework and Labs.

    Questions 1-4 represent independent multi-part items, commonly found throughout the text. The responses to each of these multi-part items are not dependent on any of its parts. Thus the items are coded in the WebAssign system separately, allowing the instructor to assign one or more of the sub-parts.

    Questions 1 and 3 are based on real data and thus, not randomized. Questions 2 and 4 contain multiple choice item types with graphs, yet the distracters are randomized.

    Question 5 is a dependent multi-part item that uses real data so it does not have randomization.

    Question 6 is a randomized version of question 5 with carefully ranged data.

    Question 7 is another example of a multi-part dependent item. This item is also comprehensive in that it requires students to apply knowledge learned from previous chapters as well as the current chapter to answer it correctly.

    Question 8 is a non-randomized item, similar in type to question 5.

    Question 9 is similar to question 8. It is a randomized version of question 8 where the context of the data presented in the item was slightly altered to allow for randomization.

    Question 10 is a multiple-choice item from the Homework with a numeric solution converted to a WebAssign randomized question.

    Question 11 is a Lab. These extensive multi-part items require students to collect, input, and analyze their unique data. Hence, their responses in subsequent steps are marked based on their data input. The Labs are generally comprehensive from previous chapters as well as the current one.

    This demo assignment allows many submissions and allows you to try another version of the same question for practice wherever the problem has randomized values.

Assignment Submission

For this assignment, you submit answers by question parts. The number of submissions remaining for each question part only changes if you submit or change the answer.

Assignment Scoring

Your last submission is used for your score.

1. 3/3 points  |  Previous Answers IDCollabStat2 6.HW.002a. My Notes
Question Part
Points
Submissions Used
1 2 3
1/1 1/1 1/1
1/50 1/50 1/50
Total
3/3
 
IQ is normally distributed with a mean of 100 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual.
X ~ Correct: Your answer is correct.
Correct: Your answer is correct. , Correct: Your answer is correct.
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2. 3/3 points  |  Previous Answers IDCollabStat2 6.HW.002b. My Notes
Question Part
Points
Submissions Used
1 2 3
1/1 1/1 1/1
1/50 1/50 1/50
Total
3/3
 
IQ is normally distributed with a mean of 100 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual. Find the probability that the person has an IQ greater than 125.

Write the probability statement.
P
x>125
Correct: Your answer is correct. The random variable is defined as capital X.


What is the probability? (Round your answer to four decimal places.)
Correct: Your answer is correct.

Sketch the graph.

Correct: Your answer is correct.
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3. –/3 points IDCollabStat2 6.HW.002c. My Notes
Question Part
Points
Submissions Used
1 2 3
–/1 –/1 –/1
0/50 0/50 0/50
Total
–/3
 
IQ is normally distributed with a mean of 100 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual. Mensa is an organization whose members have the top 2% of all IQs. Find the minimum IQ needed to qualify for the Mensa organization.

Write the probability statement.
P(X > x) =


What is the minimum IQ? (Round your answer to the nearest whole number.)
x =

Sketch the graph.

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4. 4/4 points  |  Previous Answers IDCollabStat2 6.HW.002d. My Notes
Question Part
Points
Submissions Used
1 2 3 4
1/1 1/1 1/1 1/1
1/50 1/50 1/50 1/50
Total
4/4
 
IQ is normally distributed with a mean of 100 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual. The middle 20% of IQs fall between what two values?

Write the probability statement.
P(x1 < X < x2) = Correct: Your answer is correct.


State the two values. (Round your answers to the nearest whole number.)
x1 = Correct: Your answer is correct.
x2 = Correct: Your answer is correct.

Sketch the graph.

Correct: Your answer is correct.
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5. 9/9 points  |  Previous Answers IDCollabStat2 6.HW.005. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9
1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1
1/50 1/50 1/50 1/50 1/50 1/50 1/50 1/50 1/50
Total
9/9
 
In China, 4-year-olds average 3 hours a day unsupervised. Most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.5 hours and the amount of time spent alone is normally distributed. We randomly survey one Chinese 4-year-old living in a rural area. We are interested in the amount of time the child spends alone per day.†

  • Part (a)

    In words, define the random variable X.
         Correct: Your answer is correct.

  • Part (b)

    Give the distribution of X.
    X ~ Correct: Your answer is correct.
    Correct: Your answer is correct. , Correct: Your answer is correct.

  • Part (c)

    Find the probability that the child spends less than 2 hour per day unsupervised.

    Write the probability statement.
    P
    x<2
    Correct: Your answer is correct. The random variable is defined as capital X.


    What is the probability? (Round your answer to four decimal places.)
    Correct: Your answer is correct.

    Sketch the graph.

    Correct: Your answer is correct.

  • Part (d)

    What percent of the children spend over 10 hours per day unsupervised? (Round your answer to four decimal places.)
    Correct: Your answer is correct. %

  • Part (e)

    90% of the children spend at least how long per day unsupervised? (Round your answer to two decimal places.)
    Correct: Your answer is correct. hr
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6. –/9 points IDCollabStat2 6.HW.005.general. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9
–/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
–/9
 
Suppose 4-year-olds in a certain country average 3 hours a day unsupervised and that most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.8 hours and the amount of time spent alone is normally distributed. We randomly survey one 4-year-old living in a rural area. We are interested in the amount of time the child spends alone per day.

  • Part (a)

    In words, define the random variable X.
        
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7. –/12 points IDCollabStat2 6.HW.009. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9 10 11 12
–/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
–/12
 
Thuy Dau, Ngoc Bui, Sam Su, and Lan Voung conducted a survey as to how long customers at a clothing store claimed to wait in the checkout line until their turn. Let X = time in line. Below are the ordered data (in minutes).
0.503.254.255.506.75
1.503.504.755.757.00
1.503.504.755.757.00
1.503.754.755.757.50
2.004.004.756.257.75
2.004.005.006.258.00
2.254.255.006.259.25
2.254.255.006.509.25
2.754.255.006.759.50
2.754.255.506.7510.75

  • Part (a)

    Calculate the sample mean x and the sample standard deviation s. (Round your answers to two decimal places.)
    x = min
    s = min
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8. –/10 points IDCollabStat2 6.HW.011. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9 10
–/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
–/10
 
Below is the number of AIDS cases for Santa Clara County by year of diagnosis.
Year # cases    Year # cases    Year # cases    Year # cases
1983 10 1990 225 1997 170 2004 95
1984 26 1991 243 1998 137 2005 98
1985 60 1992 357 1999 137 2006 112
1986 76 1993 382 2000 121 2007 81
1987 134 1994 277 2001 119
1988 151 1995 249 2002 131
1989 175 1996 197 2003 116

  • Part (a)

    Calculate the sample mean x and the sample standard deviation s for the number of AIDS cases. (Round your answers to two decimal places.)
    x =
    s =
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9. –/10 points IDCollabStat2 6.HW.011.general. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9 10
–/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
–/10
 
Below is the number of disease cases for a county by year of diagnosis.
Year # cases    Year # cases    Year # cases    Year # cases
1983 9 1990 225 1997 175 2004 95
1984 28 1991 243 1998 137 2005 98
1985 62 1992 343 1999 137 2006 112
1986 79 1993 372 2000 124 2007 88
1987 134 1994 293 2001 115
1988 153 1995 249 2002 131
1989 174 1996 197 2003 117

  • Part (a)

    Calculate the sample mean x and the sample standard deviation s for the number of disease cases. (Round your answers to two decimal places.)
    x =
    s =
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10. –/1 points IDCollabStat2 6.HW.013. My Notes
Question Part
Points
Submissions Used
1
–/1
0/50
Total
–/1
 
The patient recovery time from a particular surgical procedure is normally distributed with a mean of 7.6 days and a standard deviation of 2.8 days.

What is the z-score for a patient who takes 11 days to recover? (Round your answer to two decimal places.)
z =
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11. –/66 points IDCollabStat2 6.Lab.002. My Notes
Question Part
Points
Submissions Used
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66
–/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1 –/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
–/66
 

  • Lab 2 - Normal Distribution (Pinky Length) - Student Learning Outcomes

    The student will compare empirical data and a theoretical distribution to determine if an everyday experiment fits a continuous distribution.
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