A) In order to create a sampling plan, you need to follow the following 5 steps:
1) Define the sample population: who are the customers you want to contact?
The costumers who bought a new car on a certain year.
2) Define the size of population: how many customers are you going to contact?
Of the 30000 customers who bought a car, you want to contact 1000 customers.
3) Define the contact options: how are you going to contact the customers?
You have a list of names and addresses, therefore you can send a questionnaire via mail.
4) Form a sampling frame: what is the time or contact frame to get in touch with your customers?
You will send the questionnaires and you will wait two months for the answer.
5) Define the analysis method: is yours a qualitative or quantitative research?
In your case, you want a quantitative research and therefore a probabilistic sampling.
B) The 32.5% probability refers to customers having issues with the power doors locks among the costumers who had problems, it does not consider the customers who did not have any problem or those who had problems after the first 5000 miles.
C) In order to find the probability of a power door lock problem if there have been problems within the first 5000 miles, we need to consider the whole sample:
P = 13 / 1000
= 0.013
Therefore,
N = <span>0.013 </span>× 30000
= 390
Hence, the number of new cars sold that experienced a problem with the power door locks within the first 5000 miles will be 390.
You can find the number of x intercepts by setting f(x) equal to zero giving you 0=x^4-5x^2. You can factor out an x^2 and divide on both sides (when you divide 0 by anything it is still zero so the x^2 disappears), and you are left with 0=x^2-5, which you can solve easily giving you x=+/- sqrt(5). However, the original equation also has an x intercept at (0,0) which you can see by plugging 0 in for x. So the grand total of x intercepts is 3!
A postcard is in the shape of a parallelogram. A parallelogram is a quadrilateral with two pair of parallel sides, opposite sides and opposite angles are equal.
Since, the postcard has an area of 12 square inches.
Since, area of parallelogram = 
As area of parallelogram is 12, it means that the product of base and height is 12 square inches.
So, the possible dimensions of postcard are 3 inches and 4 inches and 2 inches and 6 inches.
So, base = 3 inches , height = 4 inches or base = 4 inches , height = 3 inches.
So, base = 2 inches, height = 6 inches or base = 6 inches , height = 2 inches.
Length of circular track is:
L = 2*r*pi
He run 3/4 of it so length is:
L' = 3*2/4*r*pi = 3/2*r*pi
To calculate speed of his movement we use formula:
v = s/t where s = L' and t = 1 minute 45 seconds = 105 seconds
v = L'/t =

v = r* pi/70
If we take that r = 1 answer is