3. (4 points) Positive numbers $b_{1}, b_{2}, b_{3}, b_{4}, b_{5}$ form a geometric progression. The sum of the logarithms base 2 of these numbers is 15. Find these numbers if $\log _{2} b_{1} \cdot \log _{2} b_{5}=8$.
3. $4, 4 \sqrt{2}, 8, 8 \sqrt{2}, 16$.