After 5 months of saving money, nikki had saved $350. she has now been saving for 9 months and has saved $690. find the percent of increase in the amount of nikki's savings. round the percent to the nearest tenth if necessary.

21%

Step-by-step explanation:

for the first 5 months Nikki saved $350 so she saved 70 every month. for the next 4 months she saved 690-350=340, so 85 per month. The rate of increase should be (85-70)/70=.214 round it to the nearest tenth is .21, to find the percentage just multiply 0.21 by 100 you get 21%

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3