The number of laptops sold daily at a local electronics shop has the following probability
distribution
10
12
X: # of laptops sold
P(X=x)
13
0.1
0.4
0.3
0.2
1. What is the mean of the number of laptops sold on a given day?
a) u = x. p(x) =11
b) u = x. p(x) =12
c) u= x. p(x)=13
d) None
Ans:

d is the answer

step-by-step explanation:

idn

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

step-by-step explanation:

the answer is 128