The graph shows the world human population from 10,000 BCE to 2000 CE.

Graph of world human populations (e s t) from 10000 B C E to 2000 C E in billions. Population stayed steady in 10000, 8000, 6000, and 4000 B C E. Population started to rise in 2000 B C E and 1 CE. Population rose dramatically after.

Based on the graph, what was the estimated population size in 2000?

one billion
three billion
five billion
six billion

Number of members chosen by Helena in her homeroom = 5

Mean number of tickets = 16

So, total candidates who had purchased ticket = 16 × 5= 80

Now, number of candidates chosen randomly = 10

So, total candidates who had purchased ticket = 22.5 × 10=225

No, one sample can't be a better representation by choosing randomly a group of members.

In Sample 1 , we are considering only 5 drama numbers.

And In Sample 2, we are considering 10 random samples among 75 members.

The mean in two cases varies by (22.5-16=6.5) which is large because we are considering number of tickets sold by members of club.

It would have been better if she has taken more than 3 random samples of 15  students ,among 75 students, then she would have got appropriate mean or value near the mean.