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
Increase $110,000 by 20% 3 times.
110,000 x 0.2 = 22000
(0.2 is 20% as a decimal, we needed to convert it to multiply it)
So we must add 22000 to 110,000, then take 20% of the new cost, and repeat.
Add them
110,000 + 22000 = 132000
Take 20% of new value
132000 x 0.2 = 26400
Add that
132000 + 26400 = 158400
Take another 20% of that
31680
Add them
158400 + 31680 = 190080
So the value is now $190,080
A much more efficient way to do this would be multiplying 1.2 instead of 0.2, and skipping the adding part, as you already took 100% of it and are adding 20% more.
Hope this helps!
Answer:
8.08 %
Step-by-step explanation:
Let us denote :
score X follows a normal distribution with mean
and standard deviation 
Step 2
The probability that someone scored 21.9 or less is :





Answer : 
Answer: a= -3
Step-by-step explanation:
a+3=-2
a=-3