Answer:
B) -3 (Sorry if its overwhelming)
Explanation:
First, we have the given information of the weather over a <em>2</em> and <em>1/5</em> <em>span</em>
And we are asked to find the change per hour
We can first start by finding the <em>change</em> for 2 and 1/5 hours:
- Subtract the first amount by the second amount.
= (-6 3/5) - 0
= (-6 3/5) + 0
= -6 3/5
Now that we have the change for <em>2 and 1/5 hours</em> we must find the <em>change</em> per hour:
- Divide the given dividend by the given divisor
= -6 3/5 ÷ 2 1/5
= -3
Hence, the temperature <em>change per hour</em> over a 2 1/5 hour span is -3° per hour
Answer:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like 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 heights of a population, and for this case we know the distribution for X is given by:
Where
and
We select n =100. Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:
We want this probability:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like this:

Answer:

Step-by-step explanation:

Divide 3 on both sides of the equation.

