Question

A health food store has launched a new pack of vitamins for children. The store records the number of packs ordered by a random sample of 100 online customers and the number of packs ordered by a random sample of 100 walk-in customers.

Two dot plots are shown one below the other. The title for the top dot plot is Online Customers and the title for the bottom plot is Walk In Customers. Below the line for each dot plot is written Number of Packs. There are markings from 1 to 5 on each line at intervals of one. For the top line there are 0, 0, 1, 4, 5 dots respectively for marks from 1 to 5. For the bottom line there are 3, 6, 1, 0, 0 dots respectively for marks from 1 to 5. On the right side, towards the middle of the two plots is shown a dot symbol equal to 10 customers.

Which inference can be drawn about the buying pattern of the online customers versus that of the walk-in customers?

Online customers buy an average of 4 packs compared with walk-in customers, who buy an average of 1 pack.
Online customers buy an average of 5 packs compared with walk-in customers, who buy an average of 2 packs.
Online customers buy an average of 4 packs compared with walk-in customers, who buy an average of 2 packs.
Online customers buy an average of 5 packs compared with walk-in customers, who buy an average of 1 pack.

Answer 1

Find average of both customers

Online :-

• 3+4(4)+5(5)/10
• 3+16+25/10
• 44/10
• 4.4
• 4

Offline

• 3+6(2)+3/10
• 6+12/10
• 18/10
• 1.8
• 2

option C

Answer 2

Online customers buy an average of 4 packs compared with walk-in customers, who buy an average of 2 packs.

Explanation:

Create the dot plots (see attached diagrams)

Online customers: blue dots

Walk-in customers: red dots

To calculate the average packs both groups of customers buy, sum all data values and divide by the total number of data values.

`\textsf{Average of Online customers}=( 1 * 3+ 4 * 4+ 5* 5)/(10)=4.4`

`\textsf{Average of Walk-in customers}=( 3 * 1+ 6* 2+ 1* 3)/(10)=1.8`

Online: 4.4 rounds down to 4

Walk-in: 1.8 rounds up to 2

Therefore, online customers buy an average of 4 packs compared with walk-in customers, who buy an average of 2 packs.