Final Price: 17,510.40 dollars
You multiple the tax by the original to get the amount of tax. Then you add it to your original to get total price.
<em>Hi</em><em>!</em>
<em>Answer</em><em>:</em>
<em>6</em><em> </em><em>+</em><em> </em><em>(</em><em>-9</em><em>)</em><em> </em><em>-</em><em> </em><em>(</em><em>-4</em><em>)</em><em> </em><em>-</em><em> </em><em>3</em><em> </em><em>=</em>
<em>=</em><em> </em><em>6</em><em> </em><em>-</em><em> </em><em>9</em><em> </em><em>-</em><em> </em><em>b</em><em> </em><em>(</em><em>-4</em><em>)</em><em> </em><em>-</em><em> </em><em>3</em>
<em>=</em><em> </em><em>6</em><em> </em><em>-</em><em> </em><em>9</em><em> </em><em>+</em><em> </em><em>4b</em><em> </em><em>-</em><em> </em><em>3</em>
<em>=</em><em> </em><em>-6</em><em> </em><em>+</em><em> </em><em>4b</em>
<em>=</em><em> </em><em>4b</em><em> </em><em>-</em><em> </em><em>6</em>
<em>I hope I helped you! Good luck at school! </em>
Answer:
34.87% probability that all 5 have a wireless device
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they own a wireless device, or they do not. The probability of a student owning a wireless device is independent from other students. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
81% of students own a wireless device.
This means that 
If 5 students are selected at random, what is the probability that all 5 have a wireless device?
This is P(X = 5) when n = 5. So


34.87% probability that all 5 have a wireless device