Joanne invited 21 friends to her party. Some of her friends couldn't
attend. She ended up having 16
friends at the party. How many
friends couldn't go to the party?

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Margie is practicing for an upcoming tennis tournament. her first serve is good 20 out of 30 times on average. margie wants to know the estimated probability that her first serve will be good at least four of the next six times she serves. how could she design a simulation for this scenario?

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is