REVISION-GRADE10- STATISTICS & POLYNOMIALS

 

STATISTICS

1. The mean of the following data is 50. Find the missing frequencies p1 and p2.

CIass	frequency
0-20	17
20-40	P1
40-60	32
60-80	P2
80-100	19
Total	120

                                                                                                                [Ans- p1= 28, p2=24]
   2. The median of the distribution given below is 14.4. Find the values of x and y if the total frequency is 20.

                                                                                                                    [Ans- x=4, y=6]

3. Find the median and mode of following data.

Height(in cm)	No. Of students
Less than 120	12
Less than 140	26
Less than 160	34
Less than 180	40
Less than 200	50

                                                                             [Ans – median=138.57, mode=125]
POLYNOMIALS

4. If one of the zero of the polynomial 2 x ² ‒ 4x ‒ 2k is reciprocal of the other, find the value of k.                                                                       [Ans: k= -1]

5. If α and β are the zeroes of the polynomial 2 x ² ‒ 5x ‒10, then find the Value of
  α ^-2 + β ^-2 (by                         using algebraic identity )                [Ans: 0.65]

6. Find the zeroes of the quadratic polynomial 2x ²- 9 - 3 x and verify the relationship between the                 zeroes and the coefficients.