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
Hello,
I suppose as we don't see correctely the 2nd image, that it is the first one.
Angles DOY and DKY intersept then same arc are equals.
5x+15=3x+21
==>2x=6
==>x=3 and 5x+15=5*3+15=30°, 3x+21=3*3+21=30°
Angle OYK=15x=15*3=45°
Angle ODK=9x+18=9*3+18=45° =Angle OYK which intersept the same arc.
Answer:
x = 12
Step-by-step explanation:
18:24 (comparing the same sides for the similar shapes; 18 and 24) when simplified down is equal to 3:4.
Using this 3:4 scale factor we can find the missing side x.
Solving for x :
× 16 = 12
x = 12
OR: Set up a proportion:
× 
<em>cross-multiply</em>
16 × 18 = 288
24 × x = 24x
288 = 24x
x = 12
Answer: $777.60
Step-by-step explanation:
8/100 = 0.08
0.08 * 720 = 57.6
57.6 + 720 = 777.6
<h2>
Answer:</h2>
17
<h2>
Step-by-step explanation:</h2>
Cost per Packet * Number of Packets + Shipping = Amount to Spend
0.90 * b + 2.50 = A
You can spend a maximum of $18.50
A < 18.50
Rearrange the formula to find b
Number of Packets = Amount to Spend - Shipping / Cost per Packet
18.50 - 2.50 = 16.00 / 0.9 = 17.7...
You can't have 0.7 of a packet so you have to round down to 17.
Now if you put it into the original formula:
0.90 * 17 + 2.50 = 17.80
And 17.80 is less than 18.50.