Timmy uses 1 1/2 cups of sugar for every 2 gallons of lemonade he makes. Enter the number of cups of sugar Timmy uses for 13 gallons of lemonade. Use the on-screen keyboard to enter your answer in the box below.

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