The ratio is basically finding the quotient of two numbers. If you want to find the ratio of horses to cows, divide the number of horses to that of cows.
Ratio = 18/27
When expressing it to its simplest form, make sure it is reduced. 18 and 27 are both factors of 9. So,
Ratio = 9*2/9*3
Cancelling out 9, the ratio at its simplest form is: <em>2/3</em>
Answer:
16 questions right = 80%
So Peter missed 4 questions.
Hope this helps.
:-)
I'm assuming is the shape parameter and is the scale parameter. Then the PDF is
a. The expectation is
To compute this integral, recall the definition of the Gamma function,
For this particular integral, first integrate by parts, taking
Substitute , so that :
The variance is
The second moment is
Integrate by parts, taking
Substitute again to get
Then the variance is
b. The probability that is
which can be handled with the same substitution used in part (a). We get
c. Same procedure as in (b). We have
and
Then