Stratified random sampling is a method of sampling that involves the division of a population into smaller groups known as strata. In stratified random sampling or stratification, the strata are formed based on members' shared attributes or characteristics. Stratified random sampling is also called proportional random sampling or quota random sampling.
By contrast, simple random sampling is a sample of individuals that exist in a population; the individuals are randomly selected from the population and placed into a sample. This method of randomly selecting individuals seeks to select a sample size that is an unbiased representation of the population. However, it's not advantageous when the samples of the population vary widely.
Option B. I am 100% sure that the answer is option B. Hope that helped! :D
If not then I am really sorry!
Answer:
a) First Average mean = 21
b) Current mean = 22
Step-by-step explanation:
Formula For mean =
Sum of Terms/ Number of terms
a)Sandy had test scores of 20, 25, 17, 22, and 21.
Number of terms = 5
Mean = (20 + 25 + 17 + 22 + 21)/5
= 105/5
= 21
b) On the next 3 test Sandy's score were 24, 24, and 23
To calculate this current mean, we will add the first 5 test scores, with this current 3 test scores and then find the average.
Mean = (20+ 25+ 17 +22 +21 + 24 + 24 + 23)/8
Mean = 176/8
Mean = 22
80,000 + 6,000 + 200 + 11 = 86,211 Hope this helped c:
B+11 ? I’m not sure is this high school math ?
