Answer:
(-8, 7)
Step-by-step explanation:
Imagine it as a mirror. That helped me to understand that!
Answer:
D
Step-by-step explanation:
Nicky won two races. One third of six is 2
1 lawnmower= 8hours/12 =2/3 hour
30 lawnmowers= 30*2/3hour= 20 hours
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.
