7.5 %
Step-by-step explanation:
We by finding how far from the mean the 999 volume caps are, using z score;
Z = (x – μ) / σ
Z = (999 – 998) / 7
Z = 0.143
We use the z-table to find the confidence levels;
= 85%
= 0.85
Since we are finding proportion of bottles have volumes greater than 999
mL;
1 – .85 = .15
0.15/2 = 0.075
= 7.5%