Workshop 16,17,18

• Business Math
• Tertiary Education

Starter

Find the mean of 7,8,9,6

Workshop 16,17,18

Pages 34-39

By the end of the lesson you will be able to 

1. Calculate the average of a group of numbers

2. Compute the elapsed time

3. Evaluate the business data

Facts

Finding the Average The average, or mean, is a single number used to

represent a group of numbers. The average of two or more numbers is the

sum of the numbers divided by the number of items added.

Find the average of 7, 9, 4, 6, and 4.

Find the average of 5.7, 6.3, 4.2, 5.8, and 3.4.

1. 5.0
2. 5.08
3. 2.54
4. 5.06

Find the average of 31.7, 33.9, 36.1, 33.8 (nearest tenth)

Rachel Kelley’s tips from being a bellhop were $4.00, $2.00, $3.50, $1.00,
$4.00, $2.00, $1.00, and $3.00. What was her average tip?

1. 2.58
2. 2.59
3. 2.56
4. 2.54

Find the elapsed time for someone who worked from:

a. 2:15 PM to 10:30 PM

10.30-2.15= 8.15

8 hours, 15 minutes

Important facts

You cannot subtract 45 minutes from 30 minutes unless you borrow an hour and add it to the 30 minutes. Remember that 1 hour = 60 minutes.

Find the elapsed time

8:45 am to 12:30 pm

12.30 can be written as 11.30+.60=11.90

11.90-8.45=3 hrs 45 mts

Find the elapsed time of 2:50 pm to 10:20 pm

Important fact

To find elapsed time when the time period spans 1:00 o’clock, add 12 hours to the later time before subtracting

Find the elapsed time from 10:20 AM to 3:30 PM

3.30     =(12+3)+.30= 15.30

-10.20=-10.20            =-10.20

                                             5 :10 or 5 hrs 10 min

Find elapsed time for 8:30 am to 4:30 pm

1. 8 hr 20 min
2. 8 hr 15 min
3. 8 hr 0min
4. 8 hr 14 min

Find the cost to ship each package to the indicated Rate Group in Figure W18.1.

1 lb, Rate Group 1

10 lb, Rate Group 6

Find cost to ship for 6 lb, Rate Group 5

Find the cost to ship 9.75 lb, Rate Group 6

1. 96.75
2. 29
3. 131.05
4. 47.50

Find the mean of 4.37, 3.74, 4.90, 5.74 (nearest hundredth)

Find the elapsed time 9:25 pm to 6:15 am

What are the important facts of the lesson?