Answer:
28 
Step-by-step explanation:
21/2 * 8/3 = 28
Answer:
Where
and 
Since the distribution for X is normal then the distribution for the sample mean is also normal and given by:



So then is appropiate use the normal distribution to find the probabilities for 
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean". The letter
is used to denote the cumulative area for a b quantile on the normal standard distribution, or in other words: 
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where
and 
Since the distribution for X is normal then the distribution for the sample mean
is also normal and given by:



So then is appropiate use the normal distribution to find the probabilities for 
Your answer to the question is B) 7
Answer:
im a a monkey
Step-by-step explanation:
Answer:
a = - 4, b = 5
Step-by-step explanation:
Expand the left side, then compare the coefficients of like terms.
- 3(2x² + ax + b)
= - 6x² - 3ax - 3b, compare to - 6x² + 12x - 15
Compare coefficients of x- terms
- 3a = 12 ( divide both sides by - 3 )
a = - 4
Compare constant terms
- 3b = - 15 ( divide both sides by - 3 )
b = 5