The weights of seven frogs were studied. all the weights were multiples of ten. the heaviest frog weighed 300 grams and the lightest weighed 100 grams. the median weight was 130 grams. the mean weight was 150 grams, and the mode weight was 110 grams. what is the only sequence of seven weights to fit this description?

300 + 100 + 130 + 110 + 110

100,  110,  110,  130,  , ,  300
Since 130 is the median it had to go in the middle.
Since the mode is 110, we had to have that number repeat.
(750 + 2x)/7 = 150
multiply by 7 on both sides
750 + 2x = 1050
subtract 750 from both sides
2x = 300
divide both sides by 2
x = 150
Since we can't have two 150's (because it would change the mode), we need our two numbers to be greater than 130 and add to 300;
Take 10 from 150 and add the ten to the other 150 = 140 and 160
CHECK
(100 + 110 + 110 + 130 + 140 + 160 + 300)  / 7 =   150