## Statistics Assignment for Class 9

Class 9 Statistics students should refer to the following printable assignment in Pdf in standard 9. This test paper with questions and answers for Grade 9 Statistics will be very useful for exams and help you to score good marks

### Class 9 Statistics Assignment Pdf

**Question : Give five examples of data that you can collect from day to day life.**

**Answer:**In our day to day life, we can collect the following data.

**Question : Classify the data in Q1 above as primary or secondary data.**

**Answer:**The information which is collected by the investigator himself with a definite objective in his mind is called as primary data whereas when the information is gathered from a source which already had the information stored, it is called as secondary data. It can be observed that the data in 1, 3, and 5 is secondary data and the data in 2 and 4 is primary data.

**Question : The blood groups of 30 students of Class VIII are recoded as follows:**

**A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O,**

**A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.**

**Represent this data in the form of a frequency distribution table. Which is the most common, and which is the rarest, blood group among these students?**

**Answer:**It can be observed that 9 students have their blood group as A, 6 as B, 3 as AB, and 12 as O.

**Question : The distance (in km) of 40 engineers from their residence to their place of work were found as follows:**

**5 3 10 20 25 11 13 7 12 31**

**19 10 12 17 18 11 32 17 16 2 7 9**

**7 8 3 5 12 15 18 3**

**12 14 2 9 6 15 15 7 6 12**

**Construct a grouped frequency distribution table with class size 5 for the data given above taking the first interval as 0 - 5 (5 not included). What main feature do you observe from this tabular representation?**

**Answer:**It is given that a grouped frequency distribution table of class size 5 has to be constructed. Therefore, the class intervals will be 0 − 5, 5 − 10, 10 − 15, 15 −20… By observing the data given as above, a grouped frequency distribution table can be constructed as follows.

**Question : The relative humidity (in %) of a certain city for a month of 30 days was as follows:**

**98.1 98.6 99.2 90.3 86.5 95.3 92.9 96.3 94.2 95.1**

**89.2 92.3 97.1 93.5 92.7 95.1 97.2 93.3 95.2 97.3**

**96.2 92.1 84.9 90.2 95.7 98.3 97.3 96.1 92.1 89**

**(i) Construct a grouped frequency distribution table with classes**

**84 - 86, 86 - 88**

**(ii) Which month or season do you think this data is about?**

**(iii) What is the range of this data?**

**Answer:**

**Question : The heights of 50 students, measured to the nearest centimeters, have been found to be as follows:**

**161 150 154 165 168 161 154 162 150 151**

**162 164 171 165 158 154 156 172 160 170**

**153 159 161 170 162 165 166 168 165 164**

**154 152 153 156 158 162 160 161 173 166 161**

**159 162 167 168 159 158 153 154 159**

**(i) Represent the data given above by a grouped frequency distribution table, taking**

**the class intervals as 160 - 165, 165 - 170, etc.**

**(ii) What can you conclude bout their heights from the table?**

**Answer:**

**Question : A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows:**

**0.03 0.08 0.08 0.09 0.04 0.17**

**0.16 0.05 0.02 0.06 0.18 0.20**

**0.11 0.08 0.12 0.13 0.22 0.07**

**0.08 0.01 0.10 0.06 0.09 0.18**

**0.11 0.07 0.05 0.07 0.01 0.04**

**(i) Make a grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 - 0.08, and so on.**

**(ii) For how many days, was the concentration of sulphur dioxide more than 0.11 parts per million?**

**Answer :**Taking class intervals as 0.00, −0.04, 0.04, −0.08, and so on, a grouped frequency table can be constructed as follows.

_{2}is more than 0.11 is the number of days for which the concentration is in between 0.12 − 0.16, 0.16 − 0.20,

_{2}is more than 0.11 ppm.

**Question : Three coins were tossed 30 times simultaneously. Each time the number of heads occurring was noted down as follows:**

**0 1 2 2 1 2 3 1 3 0**

**1 3 1 1 2 2 0 1 2 1**

**3 0 0 1 1 2 3 2 2 0**

**Prepare a frequency distribution table for the data given above.**

**Answer:**By observing the data given above, the required frequency distribution table can be constructed as follows.

**Question :**

**The value of π up to50 decimal places is given below:**

**3.14159265358979323846264338327950288419716939937510**

**(i) Make a frequency distribution of the digits from 0 to 9 after the decimal point.**

**(ii) What are the most and the least frequently occurring digits?**

**Answer:**

**Question : Thirty children were asked about the number of hours they watched TV programmes in the previous week. The results were found as follows:**

**1 6 2 3 5 12 5 8 4 8**

**10 3 4 12 2 8 15 1 17 6**

**3 2 8 5 9 6 8 7 14 12**

**(i) Make a grouped frequency distribution table for this data, taking class width 5 and one of the class intervals as 5 - 10.**

**(ii) How many children watched television for 15 or more hours a week?**

**Answer:**

**Question :**

**A company manufactures car batteries of a particular type. The lives (in years) of 40**

**such batteries were recorded as follows:**

**2.6 3.0 3.7 3.2 2.2 4.1 3.5 4.5**

**3.5 2.3 3.2 3.4 3.8 3.2 4.6 3.7**

**2.5 4.4 3.4 3.3 2.9 3.0 4.3 2.8**

**3.5 3.2 3.9 3.2 3.2 3.1 3.7 3.4**

**4.6 3.8 3.2 2.6 3.5 4.2 2.9 3.6**

**Construct a grouped frequency distribution table for this data, using class intervals of**

**size 0.5 starting from the intervals 2 − 2.5.**

**Answer:**A grouped frequency table of class size 0.5 has to be constructed, starting from class interval 2 − 2.5.