Answer:
D. All of the above
Step-by-step explanation:
Samples may be classified as:
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this problem:
Two random samples are selected and combined. The combination is a random sample. So A. is correct.
They are not balanced. More male professors than female are chosen. So B. is correct.
The teachers are divided into groups(male and female). And some members of each group are selected. So C. is correct.
So the correct answer is:
D. All of the above
Answer:
6
Step-by-step explanation:
Plug in 3 into both expressions
Then add those results
2(3)+21=6+21=27
3-24 =-21
-------
6 is the sum of 27 and -21
Answer:
Step-by-step explanation:
3x2−2x−5=0
Let us factorize using the split the middle term method.
On inspection we observe that middle term can be split in two parts whose product is equal to the product of first and third term.
Two terms are −5xand3x
The equation becomes
3x2+3x−5x−5=0, pairing the two and taking out common factors
⇒(3x2+3x)−(5x+5)=0,
don't forget to change the sign of −5 once placed inside the parenthesis.
⇒3x(x+1)−5(x+1)=0
⇒(x+1)(3x−5)=0
Either (x+1)=0 or (3x−5)=0
We obtain x=−1,53
or x=−1,123
Try to use long division! To calculate a fraction as a decimal, you can act like the slash is a division symbol.
So, to calculate 1/6 as a decimal, divide 1 by 6 on a sheet of paper (or a calculator) and you’ll find out what it is.
First take out the parenthese
then you can subtract 2i from -1i to get i
then add 4 to 3
hence the answer, 7/i