The correlation coefficient between two variables X and Y is 0.4. The correlation coefficient between 2X and (Y) will be :
Suppose a person would earn Rs. 10,000 in base period. Suppose the cost of living index increases by 20over base period. Then the employers of that person increase his salary by Rs. 1500. Which of the following option is TRUE?
In drawing a sample of size n under SRSWR from a population of size N, the probability that a specified member is included in the chosen sample is
If a population consists of 10 units and SRSWOR is adopted, the probability of selecting a specified sample of 2 units is :
Consider simple random sampling with replacement from a population of size N. The number of samples of size n is
The coefficient of range of the weights of 10 students from the following data:
41,20,15,65,73,84,53,35,71,55 is
In simple random sampling of n units from a population of N units the quantity [1 (n/N)] is called the
If x and y are uncorrelated variables then this implies :
In the construction of cost of living index, commodities are selected by :
For determination of mode and median graphically, one considers:
The area of a rectangle is 800sq.cm.Perimeter is 100cm.What is the length of its diagonal?
Area=lb=800,Perimeter=2(l+b)=100
l+b=50,(l+b)²=2500,l²+b²+2lb=2500,l²+b²+1600=2500
l²+b²=900,√l²+b²=30
The cost of fencing around a rectangular playground at the rate of 10 per metre is Rs.4800.If the ratio between length and breadth is 5:3,find the breadth.
Perimeter=4800/10=480
Perimeter=2(5x+3x)=480
8x=240 x=30
Breadth=3*30=90
The ratio between length and breadth of a rectangle is 4:3.Area is 343sqcm.Find length.
Let length be 4x and breadth 3x.Area=7x*x=7x²=343 x²=49
X=7 Length=4*7=28
A rectangular plot with length 10m and breadth 8m has a pavement of breadth 2m inside it.Find the area of the pavement?
xy- (x-2a)(y-2a)=80-[(10-4)*(8-4)]=80-24=56
A rectangular plot with length 12 m and breadth 8m has a pavement of breadth 2m outside it.Find area of the pavement?
(x+2a)(y+2a)-(xy)=(12+4)(8+4)-(12*8)=(16*12)-(12*8)
192-96=96
What is the perimeter of a square whose area is twice the area of a square with perimeter 20m?
When area is increased 4 times,side is doubled.
Side of given square=20/4=5cm
Side of next square=5*2=10
Perimeter=4*10=40
The side of a square is 6cm.Find the percentage increase in area if side is trebled?
Area of the square with side 6cm=36
When side is trebled ,side=3*6=18cm
Area=324,Percentage increase in area=[(324-36)/36]*100=(288/36)*100=800%
The side of a square is 5cm.Find the percentage increase in area if side is doubled.
Area of the square=s²=25
When side is doubled:side=5*2=10,therefore area=s²=100
Percent increase in area=[(100-25)/25]*100=300%
The side of a square is 8cm.What is the area of a square passing through its diagonal?
Area=s²*2=8²*2=128
If diagonal of a square is 12cm,find its area
Area=d²/2=144/2=72
If the length and breadth of a rectangle is 12m and 9m find length of its diagonal.
Diagonal = √12²+9²=15
If area of a square is 1024 sq.cm,find its side?
Side=Sqr root of Area
Side= 32
If the side of a square is 12cm,find its area?
Area=a*a
Area=12*12=144
The area of a rectangular table is 5700sq.cm.If its breadth is 95cm,what is its length?
length=Area/Breadth
Length=5700/95=60
Find the perimeter of a rectangle whose length and breadth are 45m and 70m respectively?
Perimeter=2(length+breadth)
2(45+70)=2*115=230
The radii of two spheres are in the ratio of 1:2.What is the ratio of two surface areas?
Surface area of 1st sphere=4πr1²
Surface area of 2nd sphere=4πr2²
Ratio=r1²/r2²=1/4=1:4