Answer:
Step-by-step explanation:
Let x be the random variable representing the times a fire department takes to arrive at the scene of an emergency. Since the population mean and population standard deviation are known, we would apply the formula,
z = (x - µ)/σ
Where
x = sample mean
µ = population mean
σ = standard deviation
From the information given,
µ = 6 minutes
σ = 1 minute
the probability that fire department arrives at the scene in case of an emergency between 4 minutes and 8 minutes is expressed as
P(4 ≤ x ≤ 8)
For x = 4,
z = (4 - 6)/1 = - 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.023
For x = 8
z = (8 - 6)/1 = 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.98
Therefore,
P(4 ≤ x ≤ 8) = 0.98 - 0.23 = 0.75
The percent of emergencies that the fire department arrive at the scene in between 4 minutes and 8 minutes is
0.75 × 100 = 75%
Answer:
−6a+3b+13
Step-by-step explanation:
45 multiply 1/2 and 90 put it in the calculator 90 times 0.5
Answer: False
Step-by-step explanation:
You didn't give the coordinate plane that I was supposed to use while helping you.
Answer:
Step-by-step explanation:
A discriminate of -8 is never going to give you a real root. D is wrong
You cannot have just 1 complex root, nor can you have just 1 real root unless the discriminate is 0. A and C are both wrong for the same reason. 1 complex root is impossible. They come in pairs.
So the answer is B. You have 2 complex roots.
