Consider the attached ellipse. Let the sun be at the right focus. Then perihelion is at right vertex on the x-axis and aphelion is at the left vertex on the x-axis.
The distances:
- from perihelion to the sun in terms of ellipse is a-c;
- from aphelion to the sun in terms of ellipse is a+c.
Then
Add these two equations:
and subtract first equation from the second:
Note that 
thus
The equation for the planet's orbit is
Answer:
190
Step-by-step explanation:
Data provided in the question:
Confidence level = 99%
Therefore,
α = 1% = 0.01
[ from standard normal table ]
z-value for 
= 2.58
Margin of error, E = $0.06
Standard deviation, σ = $0.32
Now,
n = 
Here,
n is the sample size (or the minimum number of gas stations )
on substituting the respective values, we get
=
= 
= 13.76²
= 189.3376 ≈ 190
Hence,
minimum number of gas stations that she should include in her sample is 190
Danville,Keflavik,Somerville,Ulsan,,Smithfield
An input-output table, like the one shown below, can be used to represent a function. Each pair of numbers in the table is related by the same function rule. That rule is multiply each input number
