Answer:
E(X) = 1.28
Var(X) = 0.6016
E(X | Y=2) = 1.6667
Var(X | Y=2) = 0.4272
Step-by-step explanation:
Answer:
4x=45
Step-by-step explanation:
Cross multiply to get a simplified equation.
4/5=9/x
4x=45
x=11.25
Step-by-step explanation:
2 digit numbers are beetween 10 and 99
We are looking for numbers in wich the unit digits is less than the ten digit
we can make notice something about this numbers
0 is the smallest postive integer so all these numbers satisfy the condition
so we have now 9 numbers
here is another remark :
- 0 < 1 < 2 < 3 <4 <5 <6 < 7 < 8 < 9
numbers from 91 to 99 satisfy the condition except 99
so here are 8 other numbers
numbers from 80 to 89 satisfy the condition except 88 and 89
so here are 7 other numbers
the numbers that satisfy the keeps decreasing by 1 each time
- 8 (91⇒98)
- 7 81⇒88 + 80
- 6 71⇒76 + 70
- 5 61⇒ 65 +60
- 4 51⇒ 54 + 50
- 3 41⇒ 43 + 40
- 2 31⇒32 + 30
- 1 21 + 20
so the total number of numbers that satisfy the condition
9+8+7+6+5+4+3+2+1= 45
In order to solve this problem, we first need to find the side lengths of the square. We know that the area of a square is one length squared, so we can set up this equation:
200 =
We solve this by taking the square root of both sides.
So, one side of the square is 14.14cm. To finish this problem, we apply the pythagorean theorem. We can do this by drawing in the diagonal to make a triangle (shown in attachment - the blue part in the second drawing is the section that we use. Please note that the drawing is not to scale)
The pythagorean theorem is
, where c squared is the diagonal of a right triangle. A squared and b squared are the other two sides. We can now plug in our numbers.
So, the diagonal length is 20 cm.
Answer: Kristin bought 6 Math books and 5 English books.
Step-by-step explanation: Let x be the number of math books and y the number of english books.
Relation: 306=26x+30y
11=x+y
Solve using elimination method so you would get that y=5 then replace y=5 in the first equation to find x which is 6