To tackle this, we will apply the compound interest formula:

where

represents the final amount after

years

denotes the initial investment

is the interest rate expressed as a decimal

indicates the frequency of interest compounding annually
Initially, for the first four years, we have:

,

,

, and as the problem does not specify the frequency of compounding, we will assume it occurs annually; thus,

. Now, let's insert these values into our formula:




For the subsequent six years, the initial amount will be the resulting figure from our prior calculation, which means

. We also know that:

,

, and

. Let's substitute these figures back into our formula:




In conclusion, Collin's account will contain <span>£3691.41 after a decade.</span>