Chapter 2.1, Problem 10E

(a)

To determine

To estimate:the 60^th percentile of the given distribution.

Answer to Problem 10E

1000 is the estimate of the 60^thpercentile of the lifetimes of 2000 lamps.

Explanation of Solution

Given:

  

Calculation:

Procedure:

Step1: Draw a horizontal line from the value 60 on the vertical axis and determine the point on the ogive where the line intersects the ogive.

Step2: Draw a vertical line from this point to the horizontal axis. The line intersects the axis at approximately 1000.

  

From the above graph, 1000 is the estimate of the 60^thpercentile of the lifetimes of 2000 lamps.

Conclusion:

Therefore, 1000 is the estimate of the 60^thpercentile of the lifetimes of 2000 lamps.

(b)

To determine

To find: the percentile for a lamp lasting for 900 hours

Answer to Problem 10E

A lamp that lasted 900 hours is at 35^th percentile.

Explanation of Solution

Calculation:

Procedure:

Step 1: Draw a vertical line from the value 900 on the horizontal axis and determine the point on the ogive where the line intersects the ogive.

Step2: Draw a horizontal line from this point to the vertical axis. The line intersects the axis at approximately 35.

  

From the above graph, a lamp that lasted 900 hours is at 35^th percentile.

Conclusion:

Therefore, a lamp that lasted 900 hours is at 35^th percentile.