WGU C955 Probability and Statistics Objective Assessment and Pre Assessment Exam Questions and Answers () (Verified by Expert)

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WGU C955 Probability and Statistics Pre Assessment Exam
Questions and Answers (Verified by Expert)

1. In a class of 25 students, the following test scores were obtained:
   31, 46, 49, 52, 55, 67, 68, 68, 69, 69, 71, 73, 73, 75, 75, 78, 79, 82, 84, 84, 85, 87,
   91, 92, 97
   Which statement is true about this distribution ANS The distribution is
   skewed tothe left.
2. In a class of 25 students, the following test scores were obtained:
   51, 59, 59, 59, 67, 68, 68, 69, 69, 71, 73, 73, 75, 75, 78, 79, 82, 84, 85, 85, 87, 91,
   92, 93, 93
   A histogram of interval width 10 starting with the interval [50, 60] was
   constructed using the above data.
   Which statement is true about this distribution as depicted by the histogram ANS It is a unimodal symmetric distribution.

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3. In a class of 25 students, the following scores were received on a quiz:
   3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 9
   For this distribution, what is the most appropriate measure of central tendency ANS Either the mean or the median
4. The following 5-number summaries were obtained for two distributions, A
   and B:
   A 3.2 4.9 5.7 5.9 8.2
   B 2.7 5.1 5.7 6.9 7.5
   The distribution of A is skewed to the right, whereas the distribution of B is
   skewed to the left.
   How are the means of the two distributions related ANS The mean of A is
   higherthan the mean of B.
5. A study is conducted to determine if there is a difference in final exam
   scores in high school classrooms when different types of instruction are
   used.The two types of instruction included in the study are direct instruction

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and computer-based instruction.
What are the explanatory (X) and response (Y) variables for this study ANS
The type of instruction is the explanatory variable (X) and the test score is the
responsevariable (Y).

6. A store asked 350 of its customers whether they were satisfied with their
   service. The responses were also classified according to the gender of the
   customers.
   Satisfied Somewhat
   Satisfied Not
   Satisfied Total
   Male 60 60 50 170
   Female 45 20 115 180
   Total 105 80 165 350
   If a person wanted to study whether the level of satisfaction is related to
   or affected by gender, what is the appropriate table of conditional probabilities ANS Satisfied Somewhat
   Satisfied Not
   Satisfied Total
   Male 35.3% 35.3% 29.4% 100%
   Female 25.0% 11.1% 63.9% 100%

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WGU C955 Probability and Statistics
Objective Assessment Exam Questions and Answers
(Verified by Expert)

1. What is 3/4 divided by 2/3?
   A) 9/8
   B) 5/12
   C) 5/7
   D) 6/7: 9/8
2. A county park has hiking paths with lengths of 1.05, 3.6, 3.17, and 2.2 miles.
   What is the total length, in miles, of hiking paths in the park?
   A) 9.02 miles
   B) 10.02 miles
   C) 10.12 miles
   D) 11.2 miles: 10.02 miles
3. If there are 2 tablespoons in 1 fluid ounce, how many tablespoons does the
   following calculation yield?

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4 fl oz – 1.5 tbsp
0.5 tbsp
1 tbsp
2.5 tbsp
6.5 tbsp: 6.5 tbsp

4. Solve for X:
   X – 5/4 = 2/3
   A) 3/12
   B) 7/12
   C) 10/12
   D) 23/12: 23/12
5. Solve for X:
   X+5/3=2/3
   A) -3
   B) -1
   C) 1
   D) 3: -1
6. Given the inequality:
   2y + 6 > 20
   Which graph is the solution?
   A) {{ y < 3 }}

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B) {{ y > 6 }}
C) {{ y > 7 }}
D) {{ y < 7 }}: {{ y > 7 }}

7. Which graph is the solution for y < 8?
   A) {{ unfilled circle on 8, arrow pointing left }}
   B) {{ filled circle on 8, arrow point left }}
   C) {{ unfilled circle on 8, arrow pointing right }}
   D) {{ filled circle on 8, arrow point right }}: {{ unfilled circle on 8, arrow pointing
   left }}
8. Which graph is the solution for 4y – 6 > 18?
   A) {{ y > 4 }}
   B) {{ y > 6 }}
   C) {{ y < 4 }} D) {{ y < 6 }}: {{ y > 6 }}
9. What is the correct line graph for y = 3x + 5?
   A) (0,5) to (2,11)
   B) (0,-5) to (2,-11)
   C) (0,3) to (2,5)
   D) (0,3) to (2,-7): (0,5) to (2,11)

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10. What is the correct line graph for y = -2x + 9?
    A) (0,9) to (4.5,0)
    B) (0,9) to (3,0)
    C) (0,-9) to (5,-19)
    D) (0,-9) to (5,-24): (0,9) to (4.5,0)
11. A normally distributed data set has a mean of 25 and a standard deviation
    of 2.
    Which percentage of the data falls between 23 and 25?
    A) 34.0
    B) 68.0
    C) 95.0
    D) 99.7: 34.0
12. A given data set is normally distributed with a mean of 200 and a standard
    deviation of 5.
    Which two values does 95% of the data fall between?