A bar graph is a graph that presents data with rectangular bars with heights or lengths proportional to the values that they represent.  

Raw data is data collected from one or many sources. It is data that has not been organised. It needs to be organised so that it can be used.

On observing the bar graph, we see that
Total number of people who took the survey = (3 + 4+ 7+ 6) = $20$
Number of people who like caramel flavour = $3$
$\therefore$ Number of people who don't prefer caramel flavoured popcorn =$20-3=17$

Arranging the heights of 12 boys in ascending order we get
$141,142,143,143,144,144,145,145,147,147,149,151$
The number of times a particular value of data occurs is known as frequency.
Here, we see there are 2 boys with height 143 cm.
Therefore, the frequency of boys with a height of 143 cm is 2.

On observing the table we see,
Number of black cars sold = $20$
Number of white cars sold = $17$

∴ Total number of black and white cars sold = $20+17=37cars$

The number of times a particular value of data occurs is known as frequency. 
 ×, ×, ÷, -, ×, +, +, ÷, ×, +, -, +, +, -, ÷, ×
Here, we observed that symbol  '-' is occurring thrice, therefore the frequency of '-' symbol is 3.

On observing the data,
Given: Red cars = $15$
           Green cars = $4$

$\therefore$ Difference between red cars sold and green cars = $15-4=11cars$

Given:
1 drop = $4$ inches of rain
Rainfall recorded on Thursday = $11$ drops
Therefore, the number of inches of rain on Thursday = $4\times 11=44inches$

By observing the graph, (1 drop = 1 inch)
Rainfall recorded on Monday = 10 inches
Rainfall recorded on Tuesday = 06 inches
Rainfall recorded on Wednesday = 08 inches
Rainfall recorded on Thursday = 11 inches
Rainfall recorded on Friday = 07 inches
Rainfall recorded on Saturday = 04 inches
Rainfall recorded on Sunday = 09 inches
From above , we can see that Thursday had the heaviest rainfall.