Statistics

Mean of twenty observations is $15$. It two observations $3$ and $14$ are replaced by $8$ and $9$ respectively, then the new mean will be

Find the value of $p$ if the Mean of the following distribution is $50$ $x$ $10$ $30$ $50$ $70$ $90$ $y$ $17$ $5p+3$ $32$ $7p-11$ $19$

The mean of the following data is $50.$ Find the value of a and hence the frequencies of $30$ and $70.$ $\begin{array}{*{20}{c}}X&{10}&{30}&{50}&{70}&{90}\F&{17}&{5a + 3}&{32}&{7a -11}&{19}\end{array}$

The frequency distribution of the marks obtained by $100$ students in a test carrying $50$ marks then the mean is Marks 0-9 10-19 20-29 30-39 40-49 No. of students 8 15 20 45 12

The median of $100$ observations grouped in classes of equal width is $25$. If the median class interval is $20-30$ and the number of observations less than $20$ is $45$, then the frequency of median class is :

Marks obtained by 40 students of a class are shown as , Marks above 10 20 30 40 50 60 70 80 Number of students 40 34 26 $f_{1}$ 6 $f_{2}$ 1 0 the mean of the distribution estimated as 35.75, the respective values of $f_{1}$ and $f_{2}$ are, if $f_{1}:::f_{2}:=:3:1$

Find the mean of the following frequency distribution: Age (in years) $18$ $19$ $20$ $21$ $22$ No. of boys $14$ $10$ $20$ $24$ $12$

Class Interval Frequency 100-12 12 120-140 14 140-160 8 160-180 6 180-200 10 mean is 145.20 If true then enter $1$ and if false then enter $0$

The following distribution gives the state-wise teacher student ratio in higher secondary schools of India. Find the mode and mean of this data. Interpret the two measures. No. of students per teacher No. of state/ U.T. 15-20 3 20-25 8 25-30 9 30-35 10 35-40 3 40-45 0 45-50 0 50-55 2

A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean number of days a student was absent. No. of days 0-6 6-10 10-14 14-20 20-28 28-38 38-40 No. of students 11 10 7 4 4 3 1

The mode of the following data is $85.7$. Find the missing frequency in it. Size Frequency 45-55 7 55-65 12 65-75 17 75-85 f 85-95 32 95-105 6 105-115 10

In the frequency distribution of discrete data given below the frequency $x$ against value $0$ is missing Variable $x$ $0$ $1$ $2$ $3$ $4$ $5$ Frequency $f$ $x$ $20$ $40$ $40$ $20$ $4$ If the mean is $2.5$ then the missing frequency $x$ will be __________

If mean and median of the distribution $a, b, c, d, e, f$ ( where $b > e > f > c > d > a$) are $20$ and $14$ respectively then mean of numbers $a-f, b-c, e, d$ will be