# Maharashtra State Board Class 7 Maths Solutions Chapter 15 Statistics Practice Set 54

**Question 1 : The daily rainfall for each day of a week in a certain city is given in millimeters. Find the average rainfall during the week. 9,11,8,20,10,16,12**

**Solution**:

Average rainfall during the week $=frac{text { sum of rainfall for each day of the week }}{text { number of days }}$ $=frac{9+11+8+20+10+16+12}{7}$

$=frac{86}{7}$

$=12.285 approx 12.29$

$therefore$ The average rainfall during the week is 12.29

$mathrm{mm}$

**Question 2 : During the annual function of a school, a Women’s Self-help Group had set up a snacks stall. Their sales every hour were worth Rs 960 ,**

**$mathrm{Rs} 830, mathrm{Rs} 945, mathrm{Rs} 800, mathrm{Rs} 847, mathrm{Rs} 970$ respectively. What was the average of the hourly sales?**

**Solution**:

Average hourly sales $=frac{text { sum of sales every hour }}{text { number of hours }}$ $=frac{960+830+945+800+847+970}{6}$

$=frac{5352}{6}$

$=operatorname{Rs} 892$

$therefore$ The average of the hourly sales was Rs 892 .

**Question 3 : The annual rainfall in Vidarbha in five years is given below. What is the average rainfall for those 5 years?**

**$900 mathrm{~mm}, 650 mathrm{~mm}, 450 mathrm{~mm}, 733 mathrm{~mm}, 400 mathrm{~mm}$**

**Solution:**

Average rainfall for 5 years $=frac{text { sum of annual rainfall in five years }}{text { number of years }}$ $=frac{900+650+450+733+400}{5}$

$=frac{3133}{5}$

$=626.6$

$therefore$ The average rainfall in Vidarbha for 5 years

was $626.6 mathrm{~mm}$.

**Question 4 : A farmer bought some sacks of animal feed. The weights of the sacks are given below in kilograms. What is the average weight of the sacks?**

**49.8,49.7,49.5,49.3,50,48.9,49.2,48.8**

**Solution**:

Average weight of the sacks $=frac{text { sum of weight of each sack }}{text { number of sacks }}$ $=frac{49.8+49.7+49.5+49.3+50+48.9+49.2+48.8}{8}$

$=frac{395.2}{8}$

$=frac{3952}{80}$

$=49.4$

$therefore$ The average weight of the sacks is $49.4 mathrm{~kg} .$

### Maharashtra Board Class 7 Maths Chapter 15 Statistics Practice Set 54 Intext Questions and Activities

**Question 1 : Rutuja practised skipping with a rope all seven days of a week. The number of times she jumped the rope in one minute every day is given below. Find the average number of jumps per minute.**

**$60,62,61,60,59,63,58 .$ (Textbook pg. no. 96)**

**Solution**:

Average $=frac{text { Sum of the number of jumps ons even days }}{text { Total number of days }}$ $=frac{[60]+[62]+[61]+[60]+[59]+[63]+[58]}{7}$

$=frac{423}{7}$

$=60.42$

$therefore$ Average number of jumps per minute $=60.42$