You need the PRODUCT() function. This unfortunately does not exist in SQL.

You could write a function that would open the record set and parse every record to return the product.

Or you could use the method used before the age of calculators - summing logarithms!

POWER(10.0, SUM(LOG10([test])))

Microsoft:

How to calculate the product of a field
Note that you will have to avoid zeroes and nulls and negative numbers, but from your sample data that shouldn't be a problem.