Mark said he can decompose into three fractions with three different numerators and the same denominator. is this possible? explain. remember, you can use equivalent fractions

You can always make an equivalent fraction by multiplying both the numerator and denominator by 2. If your starting fraction is not already fully simplified, you can divide both by 2 until you have it down to a simplified form. But, with the provided fraction, you can make equivalents and decompose it successfully.

The dean of students mailed a survey to a total of 400 students. The sample included 100 students randomly selected from each of the freshman, sophomore, junior, and senior classes on campus last term. What sampling method was used?

Solution: The sampling method used here is stratified sampling. Because the sample included the students from each of the freshman, sophomore, junior and senior classes.

Stratified sampling is is a probability sampling method and a form of random sampling in which the population is divided into two or more groups (strata) according to one or more common attributes and and a sample is selected by some design within each group.