The average playing time of compact discs in a large collection is 34 minutes, a

Question

The average playing time of compact discs in a large collection is 34 minutes, and the standard deviation is 5 minutes (a) What value is 1 standard deviation above the mean? 1 standard deviation below the mean? What values are 2 standard deviations away from the mean? 1 standard deviation above the mean 1 standard deviation below the mean 2 standard deviations above the mean 2 standard deviations below the mean (b) Without assuming anything about the distribution of times, at least what percentage of the times are between 24 and 44 minutes? (Round the answer to the nearest whole number.) At least (c) Without assuming anything about the distribution of times, what can be said about the percentage of times that are either less than 19 minutes or greater than 49 minutes? (Round the answer to the nearest whole number.) No more than (d) Assuming that the distribution of times is normal, about what percentage of times are between 24 and 44 minutes? Round the answers to two decimal places, if needed.) Less than 19 min or greater than 49 min? Less than 19 min?

Explanation / Answer

a)

1 std deviation above the mean =34+5=39

1 std deviation below the mean =34-5=29

2 std deviation above the mean =34+2*5=44

2 std deviation below the mean =34-2*5=24

b)

from Chebychev's at least (1-1/k2)*100=(1-1/22)*100 =75 %

c)

no more than (1/k2)*100 =(1/32)*100 =11.0%

d)from normal distribution

between 24 and 44 minutes =95.45%

less than 19 min or greater than 49 min =0.27 %

less than 19 min =0.13%

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.