Question 6 - Figure it out - Page 127-132 - Chapter 5 Class 8 - Tales by Dots and Lines (Ganita Prakash II)

Transcript

Question 6 There were 2 new admissions to Sudhakar’s class just a couple of days after the class average height was found to be 150.2 cm. (i) Which of the following statements are correct? Why? (a) The average height of the class will increase as there are 2 new values. (b) The average height of the class will remain the same. (c) The heights of the new students have to be measured to find out the new average height. (d) The heights of everyone in the class has to be measured again to calculate the new average height.To find the average, we need to Sum of all heights Thus, we cannot find average without knowing the heights of the new students So, option (c) is correct Question 6 There were 2 new admissions to Sudhakar’s class just a couple of days after the class average height was found to be 150.2 cm. (ii) The heights of the two new joinees are 149 cm and 152 cm. Which of the following statements about the class’ average height are correct? Why? (a) The average will remain the same. (b) The average will increase. (c) The average will decrease. (d) The information is not sufficient to make a claim about the average.The two new kids have heights of 149 and 152. Thus, Average of two new kids = (149 + 152)/2 = 301/2 = 150.5 cm Since average of two new kids (150.5 cm) is higher than the class average of 150.2, Thus, adding them to the group pulls the overall average up. So, option (b) is correct Question 6 There were 2 new admissions to Sudhakar’s class just a couple of days after the class average height was found to be 150.2 cm. (iii) Which of the following statements about the new class average height are correct? Why? (a) The median will remain the same. (b) The median will increase. (c) The median will decrease. (d) The information is not sufficient to make a claim about median.We do not know the individual heights of the original 24 students. Without seeing the list of numbers, we can't determine how adding two new numbers will shift the middle position. So, option (d) is correct