# XI_Maths_Statistics_3 Online Test

The mean of 100 observations of 50. If one of the observations which was 50 is replaced by 40, the resulting mean will be:
50
49.90
70
40
In order to make the computation of the arithmetic mean of a set of 50 numbers simpler, each observation is subtracted from 53 and the arithmetic mean of the set of differences is found to be –3.5. The arithmetic mean of the set of given numbers is:
53.07
52.93
56.50
49.50
The following item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’. You are to examine these two statements carefully and select the answers to these items using the codes given below: Codes: Assertion: The mean of x1, x2, x3, x4, x5, x6, x7, x8 and x9 which are in an arithmetic progression is x5. Reason: Mean is always the middle-most observation if the data are in an arithmetic progression.
Both A and R are individually true and R is the correct explanation of A.
Both A and R are individually true but R is not correct explanation of A.
A is true but R is false
A is false but R is true
The mean grade of a section of 20 students is 66% and that of another section of 15 students is 70%. What is the combined mean grade?
66.7%
67.7%
68.7%
69.7%
 is the deviation of a class mark  from ‘a’ the assumed mean and  is the frequency, if , then x is ____.
Lower limit
Assumed mean
Number of observations
Class size
The G.M. of the numbers  is ____.
The width of each of nine classes in a frequency distribution is 2.5 and the lower class boundary of the lowest class is 10.6. Which one of the following is the upper class boundary of the highest class?
35.6
33.1
30.6
28.1
A candidate obtains the marks as given below: English: 60, Hindi: 75, Mathematics: 63, Physics: 59 and Chemistry: 55. If the weights of 1,2,1,3,3 respectively are allotted to the subjects, the candidate’s weighted mean is:
62.4
61.5
61
60.5
Consider the following statement: If in a frequency table, the class intervals are 40-44, 45-49, 50-54, etc, then when made continuous, they will be 39.5-44.5-49.5, 49.5-54.5 etc. This statement is:
Wrong as 40-44 actually means 40-44.999…..etc and hence when made continuous, they will be 40-45, 45-50, 50-55 etc.
Wrong as there are no readings between 44 and 45, between 49 and 50 etc. and hence the correct intervals are 40-44, 45-49 etc.
Correct although the interval is actually 40-45 etc.., there is the possibility of recording errors at each interval, namely 40, 45, 50 etc. and hence the intervals should be taken as 39.5-44.5, 44.5-49.5, 49.5-54.5 etc.
Correct because the mid-values of 40-44, 45-49, 50-54 etc. and 39.5-44.5, 44.5-49.5, 49.5-54.5 etc. are the same.
The standard deviation of 6,8,10,12,14 is:
1
0
2.83
2.73
Description:

This test consist of 10 questions.Students should ideally take 10 minutes to complete the test. This test is useful for those students who are preparing for IIT JEE, AIEEE or any other engineering entrance test. This test cosist of questions from Statistics which, in general, is focused in AIEEE and IIT JEE. Last year 3 questions was asked from this chapter in AIEEE. In Statistics, deviations and variance are key topics and mostly application based questions are asked.

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