You are buying decorations for a birthday party. The before-tax total for 3 rolls of crepe paper and 20 balloons is $11.40. After you start decorating, you need more supplies. You buy 2 more rolls of crepe paper and 10 more balloons for $7.20. How much did each roll of crepe paper and each balloon cost?

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.

Sketch one cycle if the cosine function y=2cos2theta