Answer: 9.3 in.
Explanation:
Jacob wants to enlarge the larger side of the photo which is the 6 in. part, to becomes 14 in.
This means that Jacob wants to increase the larger side by a scale factor of:
= Length of enlarged picture / Length of original
= 14 / 6
= 2.33
2.33 is therefore the scale factor.
The shorter side will also increase by this same scale factor:
= 4 * 2.33
= 9.3 in.