To determine which number is not in scientific notation, we need to clarify what scientific notation is. Scientific notation involves a number expressed as [tex]\( a \times 10^b \)[/tex], where [tex]\( a \)[/tex] is a number greater than or equal to 1 but less than 10, and [tex]\( b \)[/tex] is an integer. Let's examine each provided option.
1. Number [tex]\( 25.67 \times 10^{-2} \)[/tex]:
- Here, the coefficient is [tex]\( 25.67 \)[/tex], which is not between 1 and 10.
- Thus, [tex]\( 25.67 \times 10^{-2} \)[/tex] is not in scientific notation.
2. Number [tex]\( 6.7 \times 10^3 \)[/tex]:
- The coefficient [tex]\( 6.7 \)[/tex] is between 1 and 10.
- This expression conforms to scientific notation.
3. Number [tex]\( 3 \times 10^{-8} \)[/tex]:
- The coefficient [tex]\( 3 \)[/tex] is between 1 and 10.
- This expression conforms to scientific notation.
4. Number [tex]\( 8.7 \times 10^{-5} \)[/tex]:
- The coefficient [tex]\( 8.7 \)[/tex] is between 1 and 10.
- This expression conforms to scientific notation.
Based on the criteria of scientific notation, the number that is not in scientific notation is:
[tex]\[ \boxed{25.67 \times 10^{-2}} \][/tex]
