Answer:
? = 61.5%
Explanation:
To find the percent abundance of 4d nails, you need to use the following equation:
Percent Abundance = (number of nails / total nails) x 100%
Percent Abundance (4d) = (123 / 123 + 77) x 100%
= (123 / 200) x 100%
= 0.615 x 100%
= 61.5%