Answer:
Probability that the sample mean comprehensive strength exceeds 4985 psi is 0.99999.
Step-by-step explanation:
We are given that a random sample of n = 9 structural elements is tested for comprehensive strength. We know the true mean comprehensive strength μ = 5500 psi and the standard deviation is σ = 100 psi.
<u><em>Let </em></u>
<u><em> = sample mean comprehensive strength</em></u>
The z-score probability distribution for sample mean is given by;
Z = 
~ N(0,1)
where, 
= population mean comprehensive strength = 5500 psi
= standard deviation = 100 psi
The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.
Now, Probability that the sample mean comprehensive strength exceeds 4985 psi is given by = P( > 4985 psi)
P( > 4985 psi) = P( > 
) = P(Z > -15.45) = P(Z < 15.45)
= <u>0.99999</u>
<em>Since in the z table the highest critical value of x for which a probability area is given is x = 4.40 which is 0.99999, so we assume that our required probability will be equal to 0.99999.</em>
You already have figured the main idea. In this case, the population is growing 1.9% a year. This word can be translated into: multiplied by 101.9% (100+1.9%). That means the P0 is 6 bill, the base is 101.9%(or 1.019) and the time is 50 years. The calculation would be:
<span>P(t)=P₀a^t
</span>P(t)=6 billion * 101.9%^50= 6 billion * <span>2.56276= 15.38 billion</span><span>
</span>
Answer:
100feet
Step-by-step explanation:
Given the height reached by a dolphin expressed by the equation is h = -16t^2 + 80t. At maximum height, the velocity is zero, hence;
v(t) = dh/dt = -32t + 80
0 = -32t + 80
32t = 80
t = 80/32
t = 2.5secs
Substitute t = 2.5 into the height formula h = -16t^2 + 80t
h = -16(2.5)^2 + 80(2.5)
h = -100+200
h = 100feet
Hence the maximum height the dolphin jumps is 100feet
Answer:
24
Step-by-step explanation:
---------------
24÷2=12
12+7=19
---------------
Answer:
4^-2
Step-by-step explanation:
The rules of exponents tell you ...
(a^b)(a^c) = a^(b+c)
This means ...
(4^6)(4^-8) = 4^(6-8) = 4^-2
