Answer:
b. Invalid, because the sample may not be representative of the population.
Step-by-step explanation:
A sample of around 10% of the population is needed to be representative.
In this question:
We have a population of 500,000, and a sample of 10,000.
10,000/500,000 = 1/50 = 0.02 = 2% of the population, so not representative, and option b is correct.
Answer:
24.8
Step-by-step explanation:
x = √(16)^2+(19)^2= 24.8
No because 77 is greater than the lowest number