Using proportions, it is found that the interval for the number of times Elliot must visit his parents is [14, 41].
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1 trip - 350 miles
x trips - 4900 miles
Applying cross multiplication:
[tex]350x = 4900[/tex]
[tex]x = \frac{4900}{350}[/tex]
[tex]x = 14[/tex]
He must visit his parents at least 14 times.
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1 trip - 350 miles
x trips - 14700 miles
[tex]350x = 14700[/tex]
[tex]x = \frac{14700}{350}[/tex]
[tex]x = 42[/tex]
Less than 42 trips, thus at most 41 times.
The interval is [14, 41].
A similar problem is given at https://brainly.com/question/24112433