Final answer:
No, the price change from $10 to $15 is not a straight line. The stock price fluctuations indicate that the price change is not a straight line.
Step-by-step explanation:
No, the price change from $10 to $15 is not a straight line. To determine if a price change is a straight line, we need to examine the relationship between the price and time. In this case, the stock price fluctuations are described by a linear equation: y = 15 - 1.5x, where x represents the number of hours passed in an eight-hour day of trading.
If we plot the stock price changes for January, February, and March, we can see that the graph does not form a straight line. In January, the stock price increases from $10 to $15, which represents a positive change. In February, the stock price decreases from $12 to $9, which represents a negative change. Finally, in March, the stock price increases again from $9 to $15, once again representing a positive change. The fluctuations in stock price indicate that the price change is not a straight line.