Mathematics
Assertion (A) : The mean of 15 observations was found to be 21. Later it was detected that one value 15 was wrongly copied as 18, while calculating the mean. The correct mean is 20. Reason (R) : The mean of n observations x1, x2, x3, ....., xn is . If each observation is increased by p, then the new mean is increased by p, i.e., the new mean is + p. 1. A is true, R is false 2. A is false, R is true 3. Both A and R are true 4. Both A and R are false
Related Questions
Case Study:
A school organized a Health Check Up Camp for its students. The weights (in kg) of the students of a class were recorded as below :41, 40, 36, 52, 50, 48, 47, 45,
40, 41, 42, 49, 50, 51, 38, 41,
40, 45, 40, 39, 49, 51, 48, 46,
44, 50, 57, 38, 41, 51Based on the above information, answer the following questions:
The range of the data is :
(a) 20 kg
(b) 21 kg
(c) 22 kg
(d) 23 kgMean weight of the data is :
(a) 45 kg
(b) 44.5 kg
(c) 42.5 kg
(d) 40.5 kgMedian of the data is :
(a) 44 kg
(b) 45 kg
(c) 45.5 kg
(d) 46 kgOne student weighing 45 kg, was absent on that day. Next day, the teacher added his name in the list. The average weight of the new group is :
(a) 47 kg
(b) 46.4 kg
(c) 46 kg
(d) 45 kgThe median weight of the students after adding the absentee in the list is :
(a) 45 kg
(b) 46 kg
(c) 44.5 kg
(d) 44.2 kg
Which of the following statements is/are correct?
(i) Mean of a data can be smaller than the smallest number of the data.
(ii) Mean of a data can be bigger than the largest number of the data.
Only (i)
Only (ii)
Both (i) and (ii)
Both are wrong
Average marks obtained by students of a class in an exam is 70. Which of the following is definitely incorrect?
(i) One of the students scored more than 100 marks.
(ii) One of the students scored less than 10 marks.
Only (i)
Only (ii)
Both (i) and (ii)
None of these