Find mean of the data: 20,50,80,50.

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

Can you me find the slope! (30 points)

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?