Expected Mean, E(X), is obtained by multiplying each pair of

and its

and add up the answers
E(X) = (0×0.7) + (1×0.2) + (2×0.1) = 0.4
The formula to calculate the variance, Var(X), is given by E(X)² - (E(X))²
E(X²) = (0²×0.7) + (1²×0.2) + (2²×0.1) = 0+0.2+0.4 = 0.6
(E(X))² = (0.4)² = 0.16
Var(X) = 0.6 - 0.16 = 0.44
Translating these answers into the context we have
E(Y) = 0.4×500 = $200
Var(Y) = $110
Answer:
d
Step-by-step explanation:
5x4 = 20 + 10 = 30 and it cant be a or b because they have too many bills and c doesnt have the right amount of money
Answer:
51 rows
Step-by-step explanation:
Given
Length of bookmark = 20cm
Distance between beads = 4mm
Required
Number of rows of beads
First, the distance between the rows of beads must be converted to cm
if 1mm = 0.1cm
then
4mm = 4*0.1cm
4mm = 0.4 cm
This means that each row of beads is placed at 0.4 cm mark.
The distance between each row follows an arithmetic progression and it can be solved as follows;

Where
(The last term)
(The first term)
(The distance between each row of beads)
n = ?? (number of rows)
Solving for n; we have the following;
becomes


DIvide both sides by 0.4



Add 1 to both sides


Hence, the number of rows of beads is 51