The document provides data on the costs of three helicopter models, including the number sold of each model. It asks the reader to calculate the weighted mean cost. The variable (x) is identified as the cost column, and the weights (w) are the number sold. A column is created for the calculation of w*x. These values are summed, along with the total of the weights, and the weighted mean is calculated as $545,667.

1. 3.1 - 1
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold Cost
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000

2. 3.1 - 2
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Identify which column is the variable (x) and which
column is the weights (w).
Model Number Sold Cost
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000

3. 3.1 - 3
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Identify which column is the variable (x) and which
column is the weights (w).
Model Number Sold Cost
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000

4. 3.1 - 4
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Identify which column is the variable (x) and which
column is the weights (w).
- The values you are finding the weighted mean of is the variable
 Cost is the variable (x)
Model Number Sold Cost (x)
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000

5. 3.1 - 5
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Identify which column is the variable (x) and which
column is the weights (w).
- The values you are finding the weighted mean of is the variable
 Cost is the variable (x)
- Use the Number Sold (w) as the weights. The Sunscraper will be
weighted more because more Sunscraper models were sold.
Model Number Sold (w) Cost (x)
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000

6. 3.1 - 6
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x)
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000
∑
∑ ⋅
=
w
xw
X
)(

7. 3.1 - 7
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x)
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000
∑
∑ ⋅
=
w
xw
X
)( Create a column for w∙x

8. 3.1 - 8
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000
Skycoaster 6 $365,000
High-flyer 12 $725,000
∑
∑ ⋅
=
w
xw
X
)( Create a column for w∙x

9. 3.1 - 9
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000
High-flyer 12 $725,000
∑
∑ ⋅
=
w
xw
X
)( Create a column for w∙x

10. 3.1 - 10
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000
∑
∑ ⋅
=
w
xw
X
)( Create a column for w∙x

11. 3.1 - 11
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)( Create a column for w∙x

12. 3.1 - 12
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)( Sum the column of w∙x

13. 3.1 - 13
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)( Sum the column of w∙x
Σ(w∙x) = 14,733,000

14. 3.1 - 14
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)(
Sum the column of w
Σ(w∙x) = 14,733,000

15. 3.1 - 15
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)(
Sum the column of w
Σ(w∙x) = 14,733,000Σw = 27

16. 3.1 - 16
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
∑
∑ ⋅
=
w
xw
X
)(
Σ(w∙x) = 14,733,000Σw = 27

17. 3.1 - 17
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
27
000,733,14)(
=
⋅
=
∑
∑
w
xw
X
Σ(w∙x) = 14,733,000Σw = 27

18. 3.1 - 18
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
6.666,545
27
000,733,14)(
==
⋅
=
∑
∑
w
xw
X
Σ(w∙x) = 14,733,000Σw = 27

19. 3.1 - 19
Desk Work 6: Helicopter Costs
The costs of three models of helicopters are shown
here. Find the weighted mean of the costs of the
models.
Model Number Sold (w) Cost (x) w∙x
Sunscraper 9 $427,000 9×427,000 = 3,843,000
Skycoaster 6 $365,000 6×365,000 = 2,190,000
High-flyer 12 $725,000 12×725,000 = 8,700,000
6.666,545
27
000,733,14)(
==
⋅
=
∑
∑
w
xw
X
Σ(w∙x) = 14,733,000Σw = 27
The weighted mean of the helicopter costs is $545,667.