its 30 because if you add the numbers together then you get 90, then you do 180-90 and get 90, divide 90 by 3 and get 30
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
D. -2p + q - 5 - you have to multiply, then distribute parentheses and apply plus or minus rules.
40g+300 is less than or equal to 5000
g is less than or equal to 117.5
So that is 117 guests max can be invited
Answer:
1. ∠A and ∠B are right angles. Given
2. m∠A = m∠ B All right angles are congruent.
3. ∠BEC≅ ∠AED Vertical angles are congruent
4. ΔCBE ~ ΔDAE AA
Step-by-step explanation:
A proof always begins with the givens.
1. ∠A and ∠B are right angles. -------------->Given
2. m∠A = m∠ B are equal since-----------> All right angles are congruent.
3. ∠BEC≅ ∠AED are also equal since---->Vertical angles are congruent
4. ΔCBE ~ ΔDAE since two angles are equal----------> AA
