To place the numbers in descending order, we need to convert them into standard decimal form:
- \(4.3 \times 10^{-5} = 0.000043\)
- \(6.4 \times 10^{-6} = 0.0000064\)
- \(4.3 \times 10^{-6} = 0.0000043\)
- \(6.4 \times 10^{-4} = 0.00064\)
Now, we can compare these decimal values:
- \(6.4 \times 10^{-4} = 0.00064\)
- \(4.3 \times 10^{-5} = 0.000043\)
- \(6.4 \times 10^{-6} = 0.0000064\)
- \(4.3 \times 10^{-6} = 0.0000043\)
In descending order, the numbers are:
\(6.4 \times 10^{-4}, 4.3 \times 10^{-5}, 6.4 \times 10^{-6}, 4.3 \times 10^{-6}\)