CDS || Elementary Mathematics || Statistics || Quiz

The cumulative frequency curve of a frequency distribution with 6 classes and total frequency 60 is a straight line. Consider the following statements.

i. The first and the last classes have a frequency of 10 each

ii. Both the middle classes have a total frequency of 30

iii. The frequency distribution does not have a mode

Which of the statements given above are correct?

The mean of 200 observations is 60 and standard deviation is 12 . If 10 is subtracted from each observation and then it is divided by 5 , then what will be the sum of new mean and new standard deviation ?

The mean of the following distribution is 18.

What is the value of f?

The yield of maize per plot of one acre were obtained from a number of plots from two different cities in a state and are summarized in the following table.

Which one of the following statements is correct?

There are 45 workers and 15 officers in a factory. If the mean salary of the 60 employees is 4800 and the mean salary of the workers is 5000, then the mean salary of the officers will be?