Answer:

And the best option would be:

Step-by-step explanation:
We assume that the distribution for the random variable is:

For this case we want to calculate the following probability:

And we can use the normal standard distribution or excel and we got:

And the best option would be:

This is how I did it, I really hope it helped you with your homework
Answer:
k = -
, k = 2
Step-by-step explanation:
Using the discriminant Δ = b² - 4ac
The condition for equal roots is b² - 4ac = 0
Given
kx² + 2x + k = - kx ( add kx to both sides )
kx² + 2x + kx + k = 0 , that is
kx² + (2 + k)x + k = 0 ← in standard form
with a = k, b = 2 + k and c = k , thus
(2 + k)² - 4k² = 0 ← expand and simplify left side
4 + 4k + k² - 4k² = 0
- 3k² + 4k + 4 = 0 ( multiply through by - 1 )
3k² - 4k - 4 = 0 ← in standard form
(3k + 2)(k - 2) = 0 ← in factored form
Equate each factor to zero and solve for k
3k + 2 = 0 ⇒ 3k = - 2 ⇒ k = - 
k - 2 = 0 ⇒ k = 2
Answer:
mean=86+72+16+42+16+55+16+12+91+55/2
mean=230.5
mode=16-unimodal
median the middle value but in the first arrange in ascending order.
12,16,42,55,72,86 and 91
median=55
hope it helps!