Answer:
Let X the random variable that represent the heights 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 we know that the distribution for the sample mean
is given by:
And the standard error is given by:

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 heights 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 we know that the distribution for the sample mean
is given by:
And the standard error is given by:

Plug in -6 for a and -5 for b
3(-6)^2 - 4(-5)
3(36)+20
108+20
=120
Answer:
18p = # of photographs Dillon has
Answer:
240/(v+40) + 1 > 240/v
Step-by-step explanation:
Both parties traveled a distance of 240 km.
Simpsons took off at average speed of 40 km/h & 1 hour later: 240/(v+40) + 1
Jacksons took off at average speed of v km/h: 240/v