The sum to infinity of a geometric progression is given by \(S = \frac{a}{1-r}\), where \(a\) is the first term and \(r\) is the common ratio.
For the first progression, \(a = 1\) and \(r = r\), so the sum is \(S = \frac{1}{1-r}\).
For the second progression, \(a = 4\) and \(r = \frac{1}{4}r\), so the sum is \(S = \frac{4}{1-\frac{1}{4}r}\).
Since the sums are equal, we have:
\(\frac{1}{1-r} = \frac{4}{1-\frac{1}{4}r}\)
Cross-multiplying gives:
\(1 - \frac{1}{4}r = 4(1-r)\)
\(1 - \frac{1}{4}r = 4 - 4r\)
Rearranging gives:
\(4r - \frac{1}{4}r = 4 - 1\)
\(\frac{15}{4}r = 3\)
\(r = \frac{4}{5}\)
Substituting \(r = \frac{4}{5}\) back into the sum formula for the first progression:
\(S = \frac{1}{1-\frac{4}{5}} = \frac{1}{\frac{1}{5}} = 5\)
Thus, \(r = \frac{4}{5}\) and \(S = 5\).