Answer:
Length = 3
Width = 7
Step-by-step explanation:
The perimeter is 20 feet
The area is 21 feet
Let x represent the length
Let y represent the width
20 = 2(x+y)
x+y= 20/2
x+y = 10.........equation 1
x × y= 21......equation 2
From equation 1
x= 10-y
Substitute 10-y for x in equation 2
(10-y)y= 21
10y - y^2 = 21
y^2 -10y + 21= 0
After factorization the result will be
(x-3)(y-7)
x-3= 0
x= 0+3
x= 3
y-7= 0
y= 0+7
y= 7
Hence the length is 3 and the width is 7
75.
Explanation: from 3 to 12, you add 9, and then double the 12 to get to 24, and then add 9 again to get to 33, and double it to get 66, so the pattern is to add 9 and then double.
Answer:
Step-by-step explanation:
Let many universities and colleges have conducted supplemental instruction(SI) programs. In that a student facilitator he meets the students group regularly who are enrolled in the course to promote discussion of course material and enhance subject mastery.
Here the students in a large statistics group are classified into two groups:
1). Control group: This group will not participate in SI and
2). Treatment group: This group will participate in SI.
a)Suppose they are samples from an existing population, Then it would be the population of students who are taking the course in question and who had supplemental instruction. And this would be same as the sample. Here we can guess that this is a conceptual population - The students who might take the class and get SI.
b)Some students might be more motivated, and they might spend the extra time in the SI sessions and do better. Here they have done better anyway because of their motivation. There is other possibility that some students have weak background and know it and take the exam, But still do not do as well as the others. Here we cannot separate out the effect of the SI from a lot of possibilities if you allow students to choose.
The random assignment guarantees ‘Unbiased’ results - good students and bad are just as likely to get the SI or control.
c)There wouldn't be any basis for comparison otherwise.
