Find the mean for each set of data.
3. cost of tennis shoes: $57, $63, $60, $59, $61

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?

Liz had 140 pens and inna had 100 pens. after inna gave liz some pens, liz had 3 times as many pens as inna. how many pens did inna give liz?

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.