Solve your IGNOU Doubts

Question:

The equations of two regression lines are given as follows:

$4x - 5y + 30 = 0$

$20x-9y-107 = 0$

Calculate (i) regression coefficients, $b_{yx}$ and $b_{xy}$ ; (ii) correlation coefficient r(x, y); (iii) Mean of X and Y; and (iv) the value of $\sigma_y$ if $\sigma_x = 3$ .

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Question:

Mean and Standard deviation of 18 observations are found to be 7 and 4, respectively. On comparing the original data, it was found that an observation 12 was miscopied as 21 in the calculations. Calculate correct mean and standard deviation.

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Question:

The frequency distribution of the marks obtained by the 25 students each of the two sections is given as follows:

Marks:	10-20	20-30	30-40	40-50	50-60
Section A:	2	5	10	5	3
Section B:	3	7	8	5	2

Find which section is more consistent.

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Question:

If AM and GM of two numbers are 30 and 18, respectively, find the numbers.

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Question:

Find the missing information from the following data:

	Group I	Group II	Group III	Combined
Number	50	?	90	200
Standard Deviation	6	7	?	7.746
Mean	113	?	115	116

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Question:

State whether the following statements are True or False and also give the reason in support of your answer.
a) If standard deviation of x is 5, standard deviation of y = 2x–3 is 7.
b) Mean deviation is least when calculated from the median.
c) The correlation coefficient between x and (a – x) is –1.
d) The regression coefficients byx and bxy of a data are 1.2 and 0.8, respectively.
e) If (AB) = 10, (αB) = 15, (Aβ) = 20 and (αβ) = 30 then A and B are associated.

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Question:

Draw a histogram for the following data:

Wages	40 – 49		50 – 69		70 – 99	100 – 109	110 – 119
No of workers	2		20		60	35	4

Also draw frequency polygon in the same graph.

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Question:

Find the values of a and b, if the function f given below is continuous at x = 2

$f(x) = \begin{Bmatrix} a+b, & x<2\\ a+bx+4, & x=2\\ 5, & x>2 \end{Bmatrix}$

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Question:

Draw a box plot with whisker, +ve sign and outliers for the following data: 42, 37, 28, 23, 32, 25, 26, 39, 38, 41, 22, 38, 21, 31, 26, 36, 42, 52, 50, 47, 24, 53, 28

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Question:

What do you mean by primary data and secondary data? Also give an example in each case.

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Question:

Prove that $\begin{vmatrix} a & b &c \\ b & c &a \\ c &a & b \end{vmatrix} = (a+b+c)(ab+bc+ca-a^2-b^2-c^2)$

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Question:

Evaluate the following:

a). $\int x^2e^{2x}dx$

b). $\frac{dy}{dx}$ , where $y = (4x+5)^4(9x+4)^5$

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Question:

If the universal set is $U = \left \{ 1,2,3,4,5,6,7,8 \right \}$ and $A = \left \{ 2, 3, 6, 7 \right \}$ , $B = \left \{ 4, 6, 8 \right \}$ , $C = \left \{ 6, 7,8 \right \}$ are the subsets of $U$ , then verify
a) De-Morgan’s laws
b) left distributive law

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Question:

Arrange the numbers 49, 36, 42, 19, 22, 27, 14, 13, 24, 48, 23, 28, 17, 42, 39, 45, 22, 24, 17, 41, 18, 42, 38, 43, 11, 27, 36, 13, 40, 30, 24, 10, 18, 47, 18, 19, 23, 12, 27 in stretched stemand-leaf display that has single-digit starting parts and leaves, but has stem width of 5.

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Question:

If four cards are chosen from a pack of 52 playing cards then find the number of ways that all four cards are:
a) of same suit
b) red
c) face cards
d) king
e) of different suit

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Question:

State whether the following statements are True or False and also give the reason in support of your answer.
a) Collection of rich persons in India forms a set.
b) Following rule is a function from A to B.
Image ignouassignments-ignouacademy-com--p-solve-51753

c). $\frac{d}{dx}(9-7x)^5 = 45(9-7x)^4$