Answer:
The proportion would be 0.1
Explanation:
Given, the function that shows the proportion of students in a psychology experiment who could remember an eight-digit number correctly for t minutes,
![f(t) = 0.9 - 0.4\ln(t)](https://img.qammunity.org/2020/formulas/mathematics/high-school/pvw2ddg4wlgw21jayksxwc44q25t05995t.png)
If t = 7 minutes,
![f(7) = 0.9 - 0.4\ln(7)=0.9 - 0.77836=0.12164\approx 0.1](https://img.qammunity.org/2020/formulas/mathematics/high-school/v4hpthpnp0o4rqryksdqycdqyse9vrby0o.png)
Hence, the proportion that remembered the number for 7 minutes is 0.1 ( approx )