Answer:
To convince Caesar to go to the Capitol so the conspirators could carry out the plan.
Step-by-step explanation:
The motivation behind Decius telling Caesar that his wife's dream was a misinterpretation was to convince him to go to the Capitol, where the conspirators could carry out their plan to kill him. Decius likely thought that Caesar would be more likely to go to the Capitol if he believed that his wife's dream was simply a misunderstanding, rather than a warning of impending danger.