You would do 300• 31/100 to get 90. I’m pretty sure that’s right
Answer: a) α = 0.7927, b) at u=14.8, β = 0.99767, at u = 14.9, β= 0.2073
Step-by-step explanation: a) from the question, u= population mean = 15 and x= sample mean = 14.9
σ = population standard deviation = 0.5, n = sample size = 50.
We get the probability of committing a type 1 error by using the z score.
Z = x - u/(σ/√n)
Z = 14.9 - 15/(0.5/√50)
Z = - 0.1/0.0707
Z = - 1.41.
By checking the the probabilistic value attached to this z score using a standard normal distribution table whose area is to the left of the distribution, we have that
P(z=-1.41) = 0.7927.
Hence the probability of committing a type 1 error is 0.7927
b)
at x = 14.8 ( I let ua=x=14.8)
Z = x - u/(σ/√n)
Z = 14.8 - 15/(0.5/√50)
Z = - 0.2/ 0.0707
Z = - 2.83
Using the standard normal distribution table, we have that
P(z=-2.38) = 0.00233.
But α + β = 1
Where α= probability of committing a type 1 error
β = probability of committing a type 2 error.
β = 1 - α
β = 1 - 0.00233
β = 0.99767
At x = 14.9
Z = x - u/(σ/√n)
Z = 14.9 - 15/(0.5/√50)
Z = - 0.1/0.0707
Z = - 1.41.
P(z=-1.41) = 0.7927.
α = 0.7927.
But α + β = 1
β = 1 - 0.7927
β = 0.2073
The answer is the third option, which is: Trapezoid.
The explanation for this asnwer is shown below:
1- A rectangular pyramid is a solid whose base is a rectangle and its faces are triangles.
2- When you slice or cut a solid with a plane, you obtain a shape which is known as "Cross section".
3- In this case, if these plane is perpendicular to the base but does not pass through the top vertex of the rectangular pyramid, the intersection of the plane with the pyramid, or the resulting shape will be a trapezoid.
