English

Given that X~ B(n = 10, p), if E(X) = 8. find the value of p. - Mathematics and Statistics

Advertisements
Advertisements

Question

Given that X~ B(n = 10, p), if E(X) = 8. find the value of p.

Solution

 

`X ~ B(n =10, p)`

`therefore E(X)=np`

`8=10p`

`p=0.8=4/5`

shaalaa.com
  Is there an error in this question or solution?
2013-2014 (March)

APPEARS IN

RELATED QUESTIONS

A bakerman sells 5 types of cakes. Profits due to the sale of each type of cake is respectively Rs. 3, Rs. 2.5, Rs. 2, Rs. 1.5, Rs. 1. The demands for these cakes are 10%, 5%, 25%, 45% and 15% respectively. What is the expected profit per cake?


For the bivariate data r = 0.3, cov(X, Y) = 18, σx = 3, find σy .


In a bivariate data, n = 10, `bar x` = 25, `bary` = 30 and `sum xy` = 7900. Find cov(X,Y)


 If `Σd_i^2` = 25, n = 6 find rank correlation coefficient where di, is the difference between the ranks of ith values.


The following table gives the ages of husbands and wives 

Age of wives
(in years)
           Age of husbands (in years) 
20 - 30 30 - 40 40 - 50 50 - 60 
15 - 25 5 9 3 -
25-35 - 10 25 2
35-45 - 1 12 2
45-55 - - 4 16
55-65 - - - 4

Find : (i) The marginal frequency distribution of the age of husbands.
(ii) The conditional frequency distribution of the age of husbands when the age of wives lies between
25 - 35.


The regression equation of Y on X is y = `2/9` x and the regression equation of X on Y is `x=y/2+7/6` 

Find:

  1.  The correlation coefficient between X and Y. 
  2.  `σ_y^2 if σ _x^2=4`

If the correlation coefficient between X and Y is 0.8, what is the correlation
coefficient between.
(a) X and 3Y
(b) X - 5 and Y - 3


If the correlation coefficient between X and Y is 0.8, what is the correlation coefficient between:

`"X"/2` and Y


If the correlation coefficient between X and Y is 0.8, what is the correlation coefficient between:

`"X - 5"/7` and  `"Y - 3"/8`


For a bivariate data byx = -1.2 and bxy = -0.3. Find the correlation coefficient between x and y.


If for a bivariate data `barx = 10,  bary = 12, V(X) = 9, σ_y = 4` and r = 0.6, estimate y  when x = 5.


Following tale gives income (X) and expenditure (Y) of 25 families:

Y/X 200 – 300 300 – 400 400 – 500
200 – 300 IIII I IIII I I
300 – 400 IIII IIII I
400 – 500 II

Find How many families have their income Rs. 300 and more and expenses Rs. 400 and less?


Two dice are thrown simultaneously 25 times. The following price of observation are obtained.
(2, 3) (2, 5) (5, 5) (4, 5) (6, 4) (3, 2) (5, 2) (4, 1) (2, 5) (6, 1) (3, 1) (3, 3) (4, 3) (4, 5) (2, 5) (3, 4) (2, 5) (3, 4) (2, 5) (4, 3) (5, 2) (4, 5) (4, 3) (2, 3) (4, 1)
Prepare a bivariate frequency distribution table for the above data. Also, obtain the marginal distributions.


Following data gives the age of husbands (X) and age of wives (Y) in years. Construct a bivariate frequency distribution table and find the marginal distributions.

X 27 25 28 26 29 27 28 26 25 25 27
Y 21 20 20 21 23 22 20 20 19 19 23
X 26 29 25 27 26 25 28 25 27 26  
Y 19 23 23 22 21 20 22 23 22 21

Find conditional frequency distribution of age of husbands when the age of wife is 23 years.


Construct a bivariate frequency distribution table of the marks obtained by students in English (X) and Statistics (Y).

Marks in
Statistics
(X)
37 20 46 28 35 26 41 48 32 23 20 39 47 33 27 26
Marks in
English
(Y)
30 32 41 33 29 43 30 21 44 38 47 24 32 21 20 21

Construct a bivariate frequency distribution table for the above data by taking class intervals 20 – 30, 30 – 40, ...... etc. for both X and Y. Also find the marginal distributions and conditional frequency distribution of Y when X lies between 30 – 40.


Following data gives Sales (in Lakh Rs.) and Advertisement Expenditure (in Thousand Rs.) of 20 firms.
(115, 61) (120, 60) (128, 61) (121, 63) (137, 62) (139, 62) (143, 63) (117, 65) (126, 64) (141, 65) (140, 65) (153, 64) (129, 67) (130, 66) (150, 67) (148, 66) (130, 69) (138, 68) (155, 69) (172, 68)
Construct a bivariate frequency distribution table for the above data by taking classes 115 – 125, 125 –135, ....etc. for sales and 60 – 62, 62 – 64, ...etc. for advertisement expenditure.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×