An airline wants to survey customers about their overall satisfaction. They take a random sample of 1{,}0001,0001, comma, 000 customers who have flown in the past month and email them a survey. The email also offers those who complete the survey a \$25$25dollar sign, 25 gift card that can be used almost anywhere. Which of these is the best example of nonresponse bias?

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.