INTERPRETATION OF DOT PLOT

Problem 1 :

At recess time the sales of drinks were recorded over a three minute period.

O = 100 plus, S = soy milk, C = cola, I = iced tea.

The data was : OSSCI  OCISO IOCSO OOOSC SOCOS SOOCO OIOIS

a) Draw a dot plot of the data

b) What is the mode?

Solution :

a) Dot plot of the data :

b) Mode :

In a data set most number of repeating terms is known as mode. Here O is appearing maximum number of times.

O = 100 plus

So, the mode is 100 plus.

Problem 2 :

The dot plot shows shoe sizes for students in grade 6.

a) How many students are in grade 6 at this school?

b) How many have shoe size 9 or more?

c) what percentage have shoe sizes 8 or more? 

Solution :

a) 50 students are in grade 6 at this school.

b) 22 shoe sizes

c) Total number of shoe sizes = 50

Shoe sizes 8 or more = 37

Percentage = (37/50) × 100

= 0.74 × 100

= 74%

Problem 3 :

The dot plot shows the numbers of students playing various instruments in the school orchestra.

a) How many play stringed instruments?

b) How many students are in the orchestra?

c) Find the mode of the data.

Solution :

a) In the given, stringed instruments are Violin, Cello and Double bass :

Number of students who played Violin = 9

Number of students who played Cello = 2

Number of students who played  Double bass = 1

= 9 + 2 + 1

= 12

So,12 played stringed instruments.

b) 28 students are in the orchestra.

c.) Mode :

The  most frequent entry is Violin. So, mode of the data is violin.

Problem 4 :

A class of students at a school in England were asked which summer sport they wanted to play. The choices were : T = tennis, S = swimming, C = cricket, B = basketball and F = football.

The data was : FFCTC  CSFST  TTBFS  FFCSF  TFTBC

a) Draw a horizontal dot plot of the data.

b) Find the mode of the data.

Solution :

a) Horizontal dot plot of the data.

b) Mode :

Football is entered the highest number of times.

So, mode of the data is football.

Problem 5 :

Students voted the most popular attractions at the local show to be the side shows (S), the farm animals (F), the ring events (R), the dogs and cats (D), and the wood chopping (W). The students in a class were then asked to name their favorite.

The data was : SRWSS WFDDS RRFWS RSRWS SRRRF

a) Draw a horizontal dot plot of the data.

b) Find the mode of the data.

Solution :

a) Vertical dot plot of the data.

b) Mode :

Side shows and ring events are mode.