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
ArrayAn arrangement of objects in equal rowscolumna vertical group of items often found in an arraycommutative property<span>two factors can be multiplied in either order to find the product
ex.) 3 x 4 = 12
ex.) 4 x 3 = 12</span>distributive property<span>To multiply a sum by a number, multiply each addend by the number outside the parentheses.
ex. ) 12 x 3 = (10 x 3) + (2 x 3)</span>divisionAn operation in which we make parts out of a number, which are equalequationA mathematical sentence that contains an equals sign.factorone of two or more numbers, that when multiplied together produce a given productmethoda way of doing somethingmultiplicationAn operation used for the shortening of repeated additionnumber bonda model showing part, part, whole relationshipsnumber of groupsfactor in a multiplication problem that refers to the total equal groupsnumber sentenceA complete sentence that uses numbers and symbols instead of wordspictureillustrate, show, represent, portray, or depictquotientthe answer when one number is divided by another ex.) 14 / 2 = 7repeated additionadding equal groups together ex.) 2 + 2 + 2 + 2rowa horizontal group of items often found in an arraysize of groupsfactor in a multiplication problem that refers to the how many in each grouptape diagramA drawing that looks like a segment of tape, used to illustrate number relationships.unitone segment of a partitioned tape diagramProductThe answer to a multiplication problemRepresents<span>What the number you found stands for in your problem.</span>
Answer:
100
Step-by-step explanation:
i dont know but the website i was on said 100
-21 - (-13)
-21 + 13
= -8
The answer B)
Answer:
I think its number 4
Step-by-step explanation:
but im not sure