Answer:
5
Step-by-step explanation:
Let x be the number of cell phones with keyboards needed.
40% = 
=
x+45 = 40 -----1
x+120 = 100 -----2
You would want to make the total of 1 the same as 2.
1×
: 2.5+112.5 = 100 -----3
Now 2 and 3 are equal.
x+120 = 2.5x+112.5
Isolate the x and numbers.
120-112.5 = 2.5x-x
Simplify.
1.5x = 7.5
x = 
× 7.5
x = 5
The manager of the store needs to add 5 more cell phones with keyboards.
Answer:
x = 1.723
Step-by-step explanation:
The zeros of a function f(x) are the points where the function crosses the x-axis. At these points, the function will have a value of zero, that is;
f(x) = 0
We simply graph the function and determine the points where it crosses the x-axis. From the attachment, f(x) crosses the x-axis at;
x = 1.723
The expectation value is simply obtained by multiplying the probability of each outcome by each possible value. These are then summed for each outcome to obtain the expectation value. In the board game, if there is a 60% chance that you will move 4 spaces forward (+4) and a 40% chance that you will move back 2 spaces then expected value for number of spaces is (0.6 x 4) + (0.4 x -2) = 2.4 - 0.8 = 1.6 spaces.
