I will mark first answer brainiest

Step-by-step explanation:

well the mean is adding all the numbers up and divide them by how many different numbers there are for example 7 9 18 41 9, first you would add them all together 41+18=59 59+(9+9) well 9+9=18 so 59+18=77 77+7=84 we're done with the First part, now we divide it by the number of different numbers that are shown, which is 5, so it's 84 divided by 5 which gives you the answer of 16.8

80x^8−68x^6+16^5−20x^4−4x^3+8x^2

hope i'm right lol

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation: