Answer: Nicki will have $3084 in her account after saving for 7 months.
Explanation:
Since we have given that
Amount Nick needed to purchase a pre-owned car=5999
Number of months she saved = 18
Amount she saved = $265
Total amount she saved in 18 months is given by

Now, Remaining amount she will needed will be

Now, she saved for 7 months .
According to question,
Amount after 7 months is given by

Hence, Nicki will have $3084 in her account after saving for 7 months.