Answer:
x=10
Step-by-step explanation:
3x-20=10
add 20 to both sides
3x=30
divide 3 both sides
end with x=10
3/4 / 1/6 = (3*6)/(4*1) = 18/4
18/4 = 4.5
It will take him 4.5 days to paint 3/4 of the fence.
Hope this helps! :)
Each hiker will receive 6 ounces each.
Answer:
Where
and
We select a sample of n=16 and we are interested on the distribution of
, since the distribution for X is normal then we can conclude that the distribution for
is also normal and given by:

Because by definition:



And for this case we have this:


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".
Solution to the problem
Let X the random variable that represent the IQ scores of a population, and for this case we know the distribution for X is given by:
Where
and
We select a sample of n=16 and we are interested on the distribution of
, since the distribution for X is normal then we can conclude that the distribution for
is also normal and given by:

Because by definition:



And for this case we have this:

