Select all choices which could lead to a biased result.

giving a standardized test to a class of at-risk students

asking players on a school football team how much they study

asking republicans for their opinion about a democrat-sponsored bill

collecting mosquitoes that fly into traps set throughout an area

The answers are as follows:

Biases samples are those where some members of the population are not included in the survey. These samples produce biases results.

The statements that could lead to biased results are :

1. Giving a standardized test to a class of at-risk students : Only at risk students are biased samples here.

2. Asking players on a school football team how much they study : The school football team will have a very few students as compared to the whole school.

3. Asking Republicans for their opinion about a Democrat-sponsored bill : The republicans here are a part of all the population that contains democrats, liberals and republicans. So sample is biased.

answer: 25.4 units

step-by-step explanation: radius = 12.7 units

diameter = twice the radius

diameter = 12.7 x 2

= 25.4