You want to estimate the number of students in a junior high school who ride the school bus. which sample is unbiased?

Option B - 90 students at random during lunch

Step-by-step

An unbiased sample is defined as:

A sample is an unbiased sample if every individual or the element in the population has an equal chance of being selected.

Based on this, we can eliminate:

Option A) - It prevents non-eighth-graders of the school from being represented.

Option C) - Students in a hallway might take a particular class together/may be of the same grade. This gives them an unfair advantage.

Option D) - All students who are not in chorus are not represented in this set.

the answer would be 1 1/72

step-by-step explanation:

you can rewrite the equation by separating the parts and then solving individually:

10-9=1

1/8 - 1/9=

find l c d and then combine:

1 1/72

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,