Something to be wary of when examining exchange rates.
Britain and America have different systems for showing exchange rates. In Britain, the value of a currency is measured in terms of the number of units of another currency it buys. In America, the value of a currency is the number of units it takes to buy a single unit of another currency. So in America, a strong currency is represented by a small number, whilst in Britain it is shown by a big number.
So say the exchange rate is £1 to $2. In the US, the value of the dollar (the number of dollars it takes to buy a pound) is 2, and that of the pound (the number of pounds it takes to buy a dollar) is 0.5. In the UK however, the value of the pound (the number of dollars it can buy) is 2 and the value of the dollar (the number of pounds it can buy) is 0.5.
In one sense, it does not matter which method you use, they are both accurate. However, the American system can potentially be very confusing. When the dollar strengthens, the number representing the strength of the dollar goes down, which feels somewhat counter-intuitive. That is why, if you pick up a copy of the Wall Street Journal, you will find that the numbering on the Y-Axis of graphs showing changes in exchange rates are often upside down, big number at the bottom, small number at the top, so when a currency strengthens, the line goes up instead of down.
Before you start analysing exchange rates, make sure you know what country you're in.