Answer:
Stratified sampling
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
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 question:
Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.
They could look at the length of the book and the size of the font to estimate the length of a book.
<span>To find the mean absolute deviation of the data, start by finding the mean of the data set.Find the sum of the data values, and divide the sum by the number of data values.Find the absolute value of the difference between each data value and the mean: ...<span>Find the sum of the absolute values of the differences.</span></span>
Answer:
3x+12
Step-by-step explanation:
distribute
Answer:
x=8a
Step-by-step explanation:
(3/a) x - 4 = 20
add 4 to both sides
(3/a) x = 24
Divide by 3/a
x = 24 / (3/a)
Use KCF (keep change flip)
x = (24/1) x (a/3)
x = 24a / 3
simplify
x = 8a
