Exponentials question

Exponential is the continuous version of a geometric sequence and the latter is more useful here where "the next value" means the next 10 years.

So what should i do

Use the given values to fit a geometric sequence and then use that sequence to determine the missing values.

I am still not getting the answer

Maybe post what youve tried/thought?

For m the first term is 1250 common ratio is 0.6 but i cant find the missing value???

Agreed with that, after 10 years its
1250*0.6
so after 20 its ... after 30 ... after 40 ....

How is the answer saying m is 97.2 then

What do you get for after 20 years using the geometric sequence (ar^2)?
If you get that right, its just the same again for 30, same again for 40, same again for 50.

How did I calculated after 20 years?

Its a geometric sequence.
0 years - a
10 years - ar
20 years - ar^2
....

It would be worth making sure you understand a geometric sequence and how it relates to an exponential function.

Use the given values to fit a geometric sequence and then use that sequence to determine the missing values.

How is the answer saying m is 97.2 then

Am I completely misreading this question? "Exponential decay" usually refers specifically to a model of the form $m = m_0(e^{-kt})$ where k > 0 for decay. Then when t = 0 we have m = m_0 = 1250; when t = 10 we have $750 = 1250(e^{-10t})$ giving k = (-1/10)ln(3/5).

Then for t = 50, we get an exact value of 97.2 for m as quoted