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:
A
$7,p-5
20 characters long. hahahhahahahah
In completing the square method, considering the equation X^2 - 2x + the number to be added should be<u> 1 </u>to make it a perfect square
<h3>How to know term that should added</h3>
The standard quadratic equation is of the form
ax^2 + bx + c
The completing the square method is one of the methods of solving quadratic equations
The factor to be added to the equation while using the completing the square method is of the formula
(b / 2a)^2
compared to the equation in the problem X^2 - 2x +
= (b / 2a)^2
= (2 / 2)^2
= (1)^2
= 1
Learn more on quadratic equations here:
brainly.com/question/29227857
#SPJ1
Im not quite triggered but U should go to mathantics.com or watch his videos to find it out :D
