NCERT Mathematics Class 9 Exemplar Ch 14 Statistics and Probability Part 7
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Q.7. 30 children were asked about the number of hours they watched TV programmes last week. The results are recorded as under:
Number of hours 




Frequency 




Can we say that the number of children who watched TV for 10 or more hours a week is 22? Justify your answer.
Answer: No. Infect the number of children who watch TV for 10 or more hours a week is , i.e., 6.
Q.8. Can the experimental probability of an event is a negative number? If not, why?
Answer: No, since the number of trials in which the event can happen cannot be negative, and the total number of trials is always positive.
Q.9. Can the experimental probability of an event is greater than 1? Justify your answer.
Answer: No, since the number of trials in which the event can happen cannot be greater than the total number of trials.
Q.10. As the number of tosses of a coin increases, the ratio of the number of heads to the total number of tosses will be. Is it correct? If not, write the correct one.
Answer: No. As the number of tosses of a coin increases, the ratio of the number of heads to the total number of tosses will be nearer to, not exactly.