Population = 135 students
Mean score = 72.3
Standard deviation of the scores = 6.5
Part (a): Students from 2SD and 3SD above the mean
2SD below and above the mean includes 95% of the population while 3SD includes 99.7% of the population.
95% of population = 0.95*135 ≈ 129 students
99.7% of population = 0.997*135 ≈ 135 students
Therefore, number of students from 2SD to 3SD above and below the bean = 135 - 129 = 6 students.
In this regard, Students between 2SD and 3SD above the mean = 6/2 = 3 students
Part (b): Students who scored between 65.8 and 72.3
The first step is to calculate Z values
That is,
Z = (mean-X)/SD
Z at 65.8 = (72.3-65.8)/6.5 = 1
Z at 72.3 = (72.3-72.3)/6.5 = 0
Second step is to find the percentages at the Z values from Z table.
That is,
Percentage of population at Z(65.8) = 0.8413 = 84.13%
Percentage of population at (Z(72.3) = 0.5 = 50%
Third step is to calculate number of students at each percentage.
That is,
At 84.13%, number of students = 0.8413*135 ≈ 114
At 50%, number of students = 0.5*135 ≈ 68
Therefore, students who scored between 65.8 and 72.3 = 114-68 = 46 students
Answer:This is so confusing
Step-by-step explanation:
Slope is 2/3
intercept is (0,3)
y=2/3 x + 3
To calculate the perimeter of a rectangle what you would do is add the parallel sides together so 11+11=22 and then 4+4=8 so we would add 22+8=30
So your answer would be 30
(correct me if im wrong)
Y=mx+b where m=slope=(dy/dx) and b=y-intercept (value of y when x=0)
You have two points...(1,-2),(3,2) so
m=(y2-y1)/(x2-x1)=(2--2)/(3-1)
m=4/2=2 now that you have the slope...
y=2x+b, you can use either point to solve for the y-intercept, I'll use (3,2)
2=2(3)+b
2=6+b
b=-4 so the line is:
y=2x-4