Final answer:
The command to set the displayed decimal format to 15 digits in Maple is 'Digits := 15;'. This sets the precision for floating-point numbers in Maple's output to 15 decimal places.
Step-by-step explanation:
To set the default displayed decimal format to 15 digits in Maple, you can adjust the number of digits used by Maple for floating-point arithmetic. However, the process described in the question seems to be for a different context – specifically instructions for using a statistical function on a calculator. Instead, in Maple, you would use the Digits environment variable to control the precision of numerical computations. The command for setting the decimal format to 15 digits is:
Digits := 15;
This command sets the number of decimal places that Maple will show in the output of floating-point numbers to 15. Write and execute this line in a Maple worksheet or document to change the precision.