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
The answer is 64. Hope it helps you
Answer:
a. 104
b. 102, 104, and 105
Step-by-step explanation:
a. There are 13 data points plotted on the dot line. The median lies between the 6th and 7th data point.
Thus, on the dot line, the 6th and 7th data points both fall on 104.
Therefore, median = 104
b. The dot plot shows the high temperatures that occurred more than one day are:
102, 104, and 105
A = ((6 + 7 + 6) . 8)/2
A = 19 . 4
A = 76
No.
A chord is a straight segment that joins two points of the circumference. It starts at a point in the circumference and ends at other point in the circumference.
The radius goes from the center of the circle (which is not on the circumference) to one point of the circumference.
The diameter is a chord (the largest chord possible); but not the radius.
