Answer:
19.53
Step-by-step explanation:
First let's find the new price of the backpack:
40% of 29.99 is
29.99 * 0.40 = 11.99
So the new price of the backpack is
29.99 - 11.99 = 18.00
Now let's find the price with tax
8.5% of 18.00 is
18.00 * 0.085 = 1.53
So the cost of the backpack is
18.00 + 1.53 = $19.53
Answer:
And we can find this probability using excel or the normal standard tabe and we got:
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 temperatures of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using excel or the normal standard tabe and we got: