92
Explanations:Average number of days used by the batteries = 101
Margin error = 9%
[tex]\begin{gathered} \text{Margin error = }\frac{9}{100}\times101 \\ \text{Margin error = }9.09 \end{gathered}[/tex]Minimum average number of days = 101 - Margin error
Minimum average number of days = 101 - 9.09
Minimum average number of days = 91.91
Minimum average number of days = 92 ( to the nearest whole number)
