Name: Interpretation of a Bar Graph
Uploaded: 2019-07-19
Duration: 3 min 38 s
Description: A bar graph organises categorical data into groups and represents these amounts by using bars of different lengths. Watch and interpret the information conve...

Question

In a public library, the librarian made the following observations in a particular week.

Days	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Newspaper reader	$350$	$400$	$500$	$450$	$550$	$450$
Magazine reader	$200$	$450$	$300$	$250$	$100$	$50$

(i) Draw a double bar graph choosing an appropriate scale.

(ii) On which day, the number of readers in the library was maximum?

(iii) What is the mean number of magazine readers per day.

Accepted Answer

We draw the bar graph in the following steps:

Step $1 :$ On a graph paper first we draw a horizontal line $O X$ and a vertical line $O Y$ , representing the $x -$ axis and $y -$ axis respectively.

Step $2 :$ Along $O X$ , we write the names of the days in a week by taking an appropriate uniform gaps and along $450$ , we mark the number of readers.

Step $3 :$ Choose the scale: $1$ unit $= 100$ readers

Step $4 :$ The newspaper and magazine readers for the different days are as follows:

Monday $350$ and $100$ , Tuesday $400$ and $450$ , Wednesday $500$ and $300$ , Thursday $450$ and $250$ , Friday $550$ and $100$ , Saturday $450$ and $50$ .

Step $5 :$ On $x -$ axis we draw pairs of bars of equal width and of heights for the number of newspaper and magazine readers in different days of the week.

From the given data, we have:

Total number of readers on Monday $= 350 + 200 = 550$

Total numbers of readers on Tuesday $= 400 + 450 = 850$

Total numbers of readers on Wednesday $= 500 + 300 = 800$

Total number of readers on Thursday $= 450 + 250 = 700$

Total numbers of readers on Friday $350$

Total numbers of readers on Saturday $= 450 + 50 = 500$

Therefore, the number of readers was maximum on Tuesday having $850$ readers in total.

We have,

$Mean = \frac{Sum of given observations}{Number of the given observations}$

Thus, mean number of magazine readers $= \frac{200 + 450 + 300 + 250 + 100 + 50}{6} = \frac{1350}{6} = 225$

Hence, the mean of the magazine readers are $225$ .

Class	Class VI	Class VII	Class VIII	Class IX	Class X
Total no. of students	$95$	$90$	$82$	$75$	$68$
Number of students present on that day	$92$	$85$	$78$	$69$	$62$

Month	January	February	March	April	May	June
Number of hours of sunshine in Aberdeen	$2$	$3 \frac{1}{4}$	$4$	$4 \frac{1}{2}$	$7 \frac{3}{4}$	$8$
Number of hours of sunshine in Margate	$1 \frac{1}{2}$	$3$	$3 \frac{1}{2}$	$6$	$5 \frac{1}{2}$	$6 \frac{1}{2}$

Towns	A	B	C	D
$2016$	$640000$	$830000$	$460000$	$290000$
$2017$	$750000$	$920000$	$630000$	$320000$

Towns	$A$	$B$	$C$	$D$
$2016$	$640000$	$830000$	$460000$	$290000$
$2017$	$750000$	$920000$	$630000$	$320000$

Important Questions on Bar Graphs

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