Answer:
r = 7
Step-by-step explanation:
[tex]a =5\\\\a_{3}=245\\\\a_{n}=ar^{n-1}\\\\a_{3}= 5*r^{2} \\\\5*r^{2} = 245\\\\r^{2}=\frac{245}{5}\\\\r^{2}=49 = 7^{2}\\\\r = 7[/tex]
