Concept explainers
(a)
Proportion of time that Mrs. Starnes take to finish an easy Sudoku puzzle in less than 3 minutes.
(a)

Answer to Problem 61E
Around 0.0052 of the time does Mrs. Starnes finish an easy Sudoku puzzle in less than 3 minutes.
Explanation of Solution
Given Information:
Time value,
Mean,
Standard deviation,
Calculations:
Calculate the z − score,
Use normal
See the row that starts with -2.5 and the column that starts with .06 of the standard normal probability table for
Therefore,
Around 0.0052 of the time does Mrs. Starnes finish an easy Sudoku puzzle in less than 3 minutes.
(b)
Percentage of time that Mrs. Starnes takes more than 6 minutes to complete an easy puzzle.
(b)

Answer to Problem 61E
Around 21.77% of the time Mrs. Starnes takes more than 6 minutes to complete an easy puzzle.
Explanation of Solution
Given Information:
Time value,
Mean,
Standard deviation,
Calculations:
Calculate the z − score,
Use normal probability table in the appendix, to find the corresponding probability.
See the row that starts with 0.7 and the column that starts with .08 of the standard normal probability table for
Therefore,
Around 21.77% of the time Mrs. Starnes takes more than 6 minutes to complete an easy puzzle.
(c)
Percentage of easy Sudoku puzzles completed by Mrs. Starnes between 6 and 8 minutes.
(c)

Answer to Problem 61E
Around 21.64% of theeasy Sudoku puzzles take Mrs. Starnes between 6 and 8 minutes to complete.
Explanation of Solution
Given Information:
Time value,
Mean,
Standard deviation,
Calculations:
Calculate the z − score,
Or
Use normal probability table in the appendix, to find the corresponding probability.
See the row that starts with 0.7 and the column that starts with .08 of the standard normal probability table for
Or
See the row that starts with 3.0 and the column that starts with .00 of the standard normal probability table for
Therefore,
Around 21.64% of theeasy Sudoku puzzles take Mrs. Starnes between 6 and 8 minutes to complete.
Chapter 2 Solutions
PRACTICE OF STATISTICS F/AP EXAM
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