Answer:
T = 290
Step-by-step explanation:
We can find the sum of all observations multiplying sample size (n) by sample mean (x).
Sum of all observations in the data set is,

Hope this helps!
Answer:

Step-by-step explanation:

Answer:
30
Step-by-step explanation:
15x2=30
10x3=30
Answer:
C
Step-by-step explanation:
First find how many games they need to have 90% by multiplying .9(30)=27
then, 15(.8)=12
Then 27-12=15
Answer:
Sampling is necessary because researchers in the social sciences almost never have enough resources — time or money — to collect information about the entire set of subjects of interest to them.
Step-by-step explanation:
Sampling is done because you usually cannot gather data from the entire population. Even in relatively small populations, the data may be needed urgently, and including everyone in the population in your data collection may take too long.