Answer:

Step-by-step explanation:
We are given a joint probability table.
There are four different graders in a school
1. Grade Ninth
2. Grade Tenth
3. Grade Eleventh
4. Grade Twelfth
Field trip refers to the students who will attending the amusement park field trip.
No field trip refers to the students who will not be attending the amusement park field trip.
We want to find out the probability that the selected student is an eleventh grader given that the student is going on a field trip.

Where P(eleventh and FT) is the probability of students who are in eleventh grade and will be going to field trip

Where P(FT) is the probability of students who will be going to field trip

So the required probability is

Answer:
The population in 40 years will be 1220.
Step-by-step explanation:
The population of a town grows at a rate proportional to the population present at time t.
This means that:

In which P(t) is the population after t years, P(0) is the initial population and r is the growth rate.
The initial population of 500 increases by 25% in 10 years.
This means that 
We apply this to the equation and find t.




Applying ln to both sides




So

What will be the population in 40 years
This is P(40).


The population in 40 years will be 1220.
Answer:
X =10
Step-by-step explanation:
If you have a scientific calculator that can help you a lot.
I will upload a picture you can follow to solve this problem.
Call the notebooks x, and the pencils y.
<span>3x + 4y = $8.50 and 5x + 8y = $14.50 </span>
<span>Then just solve as simultaneous equations: </span>
<span>3x + 4y = $8.50 </span>
<span>5x + 8y = $14.50 </span>
<span>5(3x + 4y = 8.5) </span>
<span>3(5x + 8y = 14.5) </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 24y = 43.5 </span>
<span>Think: DASS (Different Add, Similar Subtract). 15x appears in both equations so subtract one equation from the other. Eassier to subtract (15x + 20y = 42.5) from (15x + 24y = 43.5) </span>
<span>(15x + 24y = 43.5) - (15x + 20y = 42.5) = (4y = 1) which means y = 0.25. </span>
<span>Then substitue into equation : </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 5 + 42.5 </span>
<span>15x = 42.5 - 5 = 37.5 </span>
<span>15x = 37.5 </span>
<span>x = 2.5 </span>
<span>15x + 24y = 43.5 </span>
<span>15(2.5) + 24(0.25) </span>
<span>37.5 + 6 = 43.5 </span>
<span>So x (notebooks) are 2.5 ($2.50) each and y (pencils) are 0.25 ($0.25) each.</span>
Answer:U.S Declaration of Independence
Step-by-step explanation: