A random sample of the students of a college is carefully constructed and all of the selected students are sent a survey form. 50% of the students return the form.
Identify all of the true statements among the following.
The results are probably biased.
This is an example of stratified sampling.
The results of the survey are unbiased because there was a random sample.
This is a volunteer sample.

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expression 4s+9s represents the total number of items that will be displayed on s shelves. simplify the expression

Select the sequences that are geometric.

The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed with a mean of 12611261 chips and a standard deviation of 118118 chips. (a) determine the 2626th percentile for the number of chocolate chips in a bag. (b) determine the number of chocolate chips in a bag that make up the middle 9696% of bags. (c) what is the interquartile range of the number of chocolate chips in a bag of chocolate chip cookies?