Example: Mean (One Variable).

Production supervisor May Kitt wants to determine the average time that a certain process takes. She randomly picks six people, observes each one as he or she carries out the process, and records the time required (in minutes):

15.5

9.25

10.0

12.5

12.0

8.5

Calculate the mean of the times. (Treat all data as x–values.)

Keys:Display:

()      

(

)

 

 

 

 

 

 

 

 

 

 

 



 

 

 



Example: Weighted Mean (Two Variables).

Description:

Clears the statistics registers. Enters the first time.

Enters the remaining data; six data points accumulated.

Calculates the mean time to complete the process.

A manufacturing company purchases a certain part four times a year. Last year's purchases were:

Price per Part (x)

$4.25

$4.60

$4.70

$4.10

Number of Parts (y)

250

800

900

1000

Find the average price (weighted for the purchase quantity) for this part. Remember to enter y, the weight (frequency), before x, the price.

 

Keys:

Display:

Description:

()

 

Clears the statistics

 

 

 

registers.

￿

 

Enters data; displays n.

￿

￿ 

 

Statistical Operations 12-5

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HP 35s Scientific manual , 