Answer:
Step-by-step explanation:
We will use the binomial distribution. Let X be the random variable representing the no. of boxes Hannah buys before betting a prize.
Our success is winning the prize, p =40/100 = 0.4
Then failure q = 1-0.4 = 0.6
Hannah keeps buying cereal boxes until she gets a prize. Then n be no. times she buys the boxes.
P(X ≤ 3) = P(X=0) +P(X=1)+P(X=2)+P(X=3)
= 
+ 
+ 
+ 
= 
+
+
= ![(0.6)^{n}+n(0.4)(0.6)^{n-1}+[tex]\frac{n(n-1)(0.4)^{2}0.6^{n-2}}{2} +\frac{n(n-1)(n-2)0.4^{3}0.6^{n-3}}{6}](https://tex.z-dn.net/?f=%280.6%29%5E%7Bn%7D%2Bn%280.4%29%280.6%29%5E%7Bn-1%7D%2B%5Btex%5D%5Cfrac%7Bn%28n-1%29%280.4%29%5E%7B2%7D0.6%5E%7Bn-2%7D%7D%7B2%7D%20%2B%5Cfrac%7Bn%28n-1%29%28n-2%290.4%5E%7B3%7D0.6%5E%7Bn-3%7D%7D%7B6%7D)
Multiply the investment fraction by the corresponding return, and add the products. The given fractions add to 59%, so the remainder is 41%. (The total of the fractions is 100%—all of the portfolio.)
... 0.43*9.1% + 0.16*16.7% + 0.41*11.4%
... = 3.913% + 2.672% + 4.674% = 11.259%
(8•365)•35 is the correct answer because 8 hrs of sleep each day times 365 days in a year = 2920 hrs slept in one year. Now you must take 2920 and multiply it by the 35 years she has been alive to get 102,200 hrs of sleep.
Answer:
x = 1 , 7
Step-by-step explanation:
Solution:-
- The given equation is as follows:
y = x^2 - 8x + 7
- We can solve the above equation by either making factors or by using Quadratic formula.
Factor Approach:
- Using the constant "7" at the end of the quadratic equation we will determine two integer multiples such that their additions/subtraction results in "-8".
- So the only factor of "7" are:
7 x 1 = 7
-7 x -1 = 7
- We see that addition/subtraction of first (7 , 1 ) does not results in "-8", However, the sum of ( -1 , -7 ) = -1 - 7 = -8. So the correct factors are ( -1 , -7 ). So we replace "-8x" with our factors "-1x" and "-7x":
x^2 -x -7x + 7 = 0
- Take common multiples out of pair of two terms:
x*(x-1) -7*(x-1) = 0
(x-7)*(x-1) = 0
- So we equate each term in bracket with "0" and evaluate the values of x:
(x-7) = 0 , x = 7
(x-1) = 0 , x = 1
- So the solution to the quadratic equation is:
x = 1 , 7
