Yes: 0.7669 divided by 100 multiplied by 116 equals 0.8896.
And .8896 is less than .8979
So .8979 is 17% greater than .7669 That does not mean the value of the pound has fallen by 17%. Your basic premise is wrong.

When calculating how much something has fallen (or risen) your base value (100%) is the point at which you started.
So with an opening rate of 1.3030, and a closing rate of 1.1137 the reduction of the rate is (roughly) 14.5%
If you have problems seeing this. Take an item costing £10. If the price goes up to £15 then that is a 50% increase (50% of the original £10)
But if you start with an item at £15 and reduce the price to £10 then that is not a 50% reduction, because you base the percentage on the original price (£5 reduction based on £15 start price is a 33.33% reduction).