Final answer:
The BCG business portfolio model uses a horizontal axis to represent the relative market share of an SBU. A relative market share of 10 means a strong market position, while a relative market share of 0.1 indicates a weaker market position.
Step-by-step explanation:
The BCG business portfolio model uses a horizontal axis to represent the relative market share of a Strategic Business Unit (SBU). A relative market share of 10 at the left end of the scale means that the SBU has 10 times the share of its largest competitor, indicating a strong market position. On the other hand, a relative market share of 0.1 at the right end of the scale means that the SBU has only 10 percent of the share of its largest competitor, indicating a weaker market position.