Answer:
The sample size needed to be taken is approximately 74.
Step-by-step explanation:
To get alpha; we have 1 - 0.95 = 0.05
Therefore, 
The we look up z* in a Standard Normal table where α = 0.025 area in each tail.
From the table, z* = 1.96
From the question variance is 484, then the standard deviation is 22
Standard deviation = 
And margin of error is 5 or less
The formula for margin of error is given as:
margin of error = 
The approximate value of n is 74.
Answer:
Step-by-step explanation:
The equation of a quadratic function in vertex form is given by:
Where (h,k) is the vertex.
It was given in the question that the vertex of the parabola is (-1,4).
When we substitute the vertex into the formula we get:
The parabola also passes through (4,19) hence it must satisfy its equation.
We divide both sides by 25 to get:
Hence the quadratic function is:
It should be 5. When you distribute the 4, it turns into 4x then (4•-7) = -28. Add 28 to -8 and you get 20. Divide 4 on Both sides and X=5
Answer:
D = rt
b, slower plane
8.5(3b) - 8.5(b) = 1649
25.5b - 8.5b = 1649
17b = 1649
b = 97mph
3b = 291mph
