A teacher is interested in whether there is an association between how alert her students are and whether or not they drink coffee. She asks each of her students to indicate if they drink coffee regularly, and she categorizes each student's alertness level as alert, somewhat alert, or not alert (3 levels) based on her observations over a week long period of time. After organizing the data, she plans to conduct a chi-square test. Given these observed frequencies, what is the calculated chi-square value?

Which equation matches the graph shown ?

What is the perimeter of trapezoid jklm? + units 2 + + units 9 + units 9 + + units

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.