This table shows the number of different sized pipes that have been used at Highfield Builders in January. The pipes are grouped according to the size of their diameter.
January: Number of Pipes Used (by Grouped Size)
Diameter (cm)
35-39
40-44
45-49
50-54
55-59
Frequency
8
10
13
3
1
The manager thinks that the mean diameter of pipe used must be in the 45-49 cm group as this is the group
most used.
Is the manager correct?
Show your working out and write the answer in the box below.
(5 marks)

No

Mean diameter = 44, which is in the 40 - 44 cm group

Step-by-step explanation:

Given the data:

Diameter (cm) - mid point(X) - frequency(F) - - FX

35-39 - - - - 37 - - - - 8 - - 296

40-44 - - - 42 - - - 10 - - - 420

45-49 - - - 47 - - - 13 - - - 611

50-54 - - - 52 - - - 3 - - - 156

55-59 - - - 57 - - - 1 - - - 57

Mean of grouped data:

Sum of (F × X) / sum of F

1540 / 35 = 44

part a

x     y

0     8

1     7.5

2     7

3     6.5

4     6

5     5.5  

for every hour i deducted .5 inches from the length of the candle

part b

it is a function because for every x value there is only one y value

part   c

for every x value there is only one y value

x       y

0       8

1       7.6

2       7.2

3       6.8

step-by-step explanation:

a) y = -3x +2

b) y = 1/2x -6

these 2 can be combined into one equation.

-3x +2 = .5x -6

8 = 3.5x

x = 8 / 3.5 = 2.2857142857

y = -3 * (8 / 3.5) +2

y = (-24 / 3.5) + 2

y = -4.8571428571

step-by-step explanation: