The frequency of revision times is given by the product of the frequency
density value and the class width.
Correct response:
- The number of students are <u>72 students</u>
<h3>Methods of calculation using a histogram</h3>
The estimate of the number of students who revised for less than 45
minutes is given by the area, <em>A,</em> under the histogram to the left of the 45
minute mark as follows;
Frequency, f = Frequency density × Class width
Number of students = ∑f
Therefore;
A = 5 × 2 + 10 × 2.2 + 20 × 1.6 + 10 × 0.8 = 72
- The number of students that revised for less than 45 minutes = <u>72 </u>students
Learn more about histograms here:
brainly.com/question/17139138
180 - 64 = 116
116 / 2 = 58 :)
Check: 58 + 58 + 64 = 180
If it is a square, subtract (90+ whatever the other angle is) from 360. If it is a triangle than add 90 plus whatever other number the other angle is then subtract it from 180. A triangle is 180 degrees, and a square is 360 degrees.
The answer is the first chart which would be A
Law of Sines can help with this problem. Law of Sines can help find a missing angle or side if given two sides with respective opposite angles or two angles with respective sides. The formula for Law of Sines is sin(A)/a = sin(B)/b. A and B are the angles and a and b are the sides opposite the angles. Hopefully, the picture above helps you visualize everything.
Anyways, we know two sides and one angle, so Law of Sines is possible to use. The side opposite the right angle is 11. So, we have sin(90)/11. The other angle, we're looking for but we do know the side. The side opposite of angle M is 5. So, we have sin(M)/5. The Law of Sines formula tells us that Sin(A)/a = Sin(B)/b = Sin(C)/c but we don't need all the angles but just angle M. So we're going to just use Sin(A)/a = Sin(B)/b. We have already set up the equations so plug them in.
Sin(90)/11 = Sin(M)/5. Cross multiplication will get 5 × Sin(90) = Sin(M) × 11.
Sin(90) = 1. So, we get 1 × 5 and get after simplifying, 5 = Sin(M) × 11. We divide both sides by 11 to get Sin(M) by itself.
5/11 = Sin(M). Now we run into a problem. How do we get the angle M? We do the inverse sin or sin^-1 key if you're using a calculator. So, (5/11)sin^-1 = M. Our final answer is angle M = 27.03569... Hope this helped!
Side Notes: Make sure if you're using a calculator that you're in degrees and NOT radians unless the question calls for radians. Also, if you wanted to find all the angles of the triangle then once you find M, you could add that to the 90 degree angle and then subtract that from 180. You will find the other angle since you know two of them and there are only three of them that have to add to 180 degrees. I just like triangles, ;-) Good luck!