What are two main purposes for using repetition when conducting experiments?

Explanation:

The experiments are the scientific procedures which are performed to analyze and determine the cause of natural phenomena. The repetition is a process which involves redoing the experimental procedure or a particular step to yield results which will be useful for framing the results.

The two main purposes for using the repetition in experiments are:

1. The similarities in the data obtain after every trial can suggest the correct methodology has been used.

2. The data obtain after repetition will be reliable, accurate and acceptable for framing the results.  

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

the answer is 3.1 his answer is wrong mines is right