Compute the mean of the following data, using direct method:
Give one example of a situation in which
(i) the mean is an appropriate measure of central tendency.
(ii) the mean is not an appropriate measure of central tendency but the medians is an appropriate measure of central tendency.
The length of 40leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:
(i) Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
(ii) Is there any other suitable graphical representation for the same data?
(iii) Is it correct to conclude that the maximum number of leaves are 153mm long? Why?
Given that Xˉ is the mean and σ2 is the variance of n observations X1,X2...Xn . Prove that the mean and variance of the observations aX1,aX2,aX3....aXn are axˉ and a2σ2 respectively (a=0) .
The mean of 100 numbers observations is 50 and their standards deviation is 5. The sum of all squares of all the observations is (a)50,000 (b) 250,000 (c) 252500 (d) 255000
For a group of 200 candidates the mean and S.D. were found to be 40 and 15 respectively. Later on it was found that the score 43 was misread as 34. Find the correct mean and correct S.D.
To find out the concentration of SO2 in the air (in parts per million, i.e., ppm), the data was collected for 30 localities in a certain city and is presented below:
|Concentration of SO2 (in ppm)|| Frequency|