Final answer:
Kirkpatrick Macmillan is credited with inventing the first pedal bicycle in 1839. John Kemp Starley and John Boyd Dunlop made significant later contributions to the development of bicycles. The invention of the radio is attributed to Guglielmo Marconi.
Step-by-step explanation:
The person credited with inventing the first pedal bicycle in 1839 is Kirkpatrick Macmillan. This Scottish blacksmith is believed to have attached pedals to the front wheel of a traditional push bike, creating a more sophisticated means of propulsion. It should be noted that there are debates around this claim, but Macmillan is often recognized for this invention. Meanwhile, John Kemp Starley developed the first modern bicycle, the safety bicycle, in 1885, and John Boyd Dunlop invented the practical pneumatic tire for the bicycle in 1887.
The invention of the radio, another transformative technology, does not involve any of the individuals mentioned in the question about the bicycle. Instead, the invention of the radio is attributed to Guglielmo Marconi.