Answer:
p(4p - 9) =12 ⇒ 4p² - 9p = 12 ⇒ 4p² - 9p - 12 = 0
- This is a quadratic equation
p(4p - 9) - 12 ⇒ 4p² - 9p - 12
- This is a quadratic expression
20 % OF 141 IS The right answer
hope that helps
Compare the impure one, with the rest of the pure gold ones.
i think.
Answer:
Step-by-step explanation:
Since the life span of the battery pack is known to be Normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = life spans of battery packs.
µ = mean life span
σ = standard deviation
From the information given,
µ = 250 hours
σ = 20 hours
The probability that a battery pack lasts longer than 260 hours. It is expressed as
P(x > 260) = 1 - P(x ≤ 260)
For x = 260
z = (260 - 250)/20 = 0.5
Looking at the normal distribution table, the probability corresponding to the z score is 0.69
The percentage of battery packs that lasts longer than 260 hours is
0.69 × 100 = 69%
Answer:
Mean = 16.5
Variance = 35.55
Step-by-step explanation:
<u> x P(x) x. P(x) x² x². P(x)</u>
6 0.10 0.6 36 3.6
12 0.35 4.2 144 50.4
18 0.25 4.5 324 81
<u> 24 0.30 7.2 576 172.8</u>
∑x P (x) 16.5 ∑x² P (x) 307.8
The expected value of x E[X] gives the mean where X is the discrete random variable with the given probabilities.
Mean is given by E(X)= ∑x P (x) = 16.5
Similarly the variance is also calculated using the expected value of X and X².
Variance is given= E(X)²- [E(X)]²= 307.8- (16.5)²= 307.8-272.25 = 35.55