Question

12. Consider the following frequency distribution which gives the weights of 38 students of a
class:
Weights (kg) 31-35 36-40 41-45 46-50 51-55 56-60 61-65 66-70 Total
No. of Std. 19 15 14 13 1 2 2 2 38
i. Find the probability that the weight of a student in the class lies between 36-45 kg.
ii. Give one event in this context having probability zero.
ii)one​

Answer 1

Answer:

i) 29/106

ii) student having weight less than equal to 30 or more than equal to 71 kg will have probability = 0

Answer 2

Answer:

(i) 0.763

(ii) Probability that the weight of student is below 31 kg

Step-by-step explanation:

We are given the following frequency distribution which gives the weights of 38 students of a  class :

    Weights (kg)              No. of Students

          31-35                              19

         36-40                              15

         41-45                               14

         46-50                              13

         51-55                                1

        56-60                                2

        61-65                                 2

        66-70                              2                

                                            Total = 38

(i) Probability that the weight of a student in the class lies between 36-45 kg = Number of students having weights between 36-45 kg ÷ Total students

 =   $\frac{15 + 14}{38}$ = $\frac{29}{38}$ = 0.763

(ii) One event in this context having probability zero is that if we ask to find the probability that the weight of student is below 31 kg as in this case we don't have any data. Hence, probability will be zero.