A: Suppose Mr. Moore decides to use 20 seventh graders as the sample. Is this sample a random sample? Explain your reasoning.
Ans: No, because he only chose the seventh graders which is invalid since he wants to have to use the mean height which involves the 6th, 7th and 8th graders.
B: Mr. Moore decides to use a random number generator to select 20 students from the school. Suppose that when choosing 20 students using the random generator on the graphing calculator, Mr. Moore’s sample is all eighth graders. Does that mean the sample is not a random sample? Explain your reasoning.
Ans: No, it is still a random sample. Since he is using a random generator, there is a possibility that the random generator would pick all students from the 8th grade. Unlike the first one, the random generator is not biased towards any grade, it is just a coincidence.
What is the expression? Tell me and I will help you.
Word form:
Two and seven hundred eighty-nine thousandths
Expanded form:
2
+ 0.7
+ 0.08
+ 0.009
So the first one, 1.2 >11/5. and the second one 1/3> 1/2
