Partial products function

To use this function, choose Calc > Calculator.

Stores the product of the first i rows of the input column in the i^th row of the storage column. For example, if the first three rows of the input column C1 contain the values 2, 5, and 3, then the first three rows of the storage column will contain 2 (equal to 2 * 1), 10 (2 * 5), and 30 (2 * 5 * 3).

Syntax

PARP(number)

For number, specify the input column.

Example

An investment manager wants to know how long it takes for an investment to double, based on average annual interest rates over the last 20 years. The manager enters the expression PARP (C2) and stores the results in C3.

C1	C2	C3
Year	Interest rate	Compound interest rate
1	1.03	1.03000
2	1.05	1.08150
3	1.06	1.14639
4	1.04	1.19225
5	1.04	1.23994
6	1.04	1.28953
7	1.06	1.36690
8	1.05	1.43525
9	1.04	1.49266
10	1.03	1.53744
11	1.05	1.61431
12	1.06	1.71117
13	1.04	1.77962
14	1.06	1.88639
15	1.05	1.98071
16	1.04	2.05994
17	1.05	2.16294
18	1.07	2.31435
19	1.06	2.45321
20	1.06	2.60040

Based on the partial products in C3, the manager determines that the compound interest rate is higher than 2 in year 16. Thus, the original investment would have doubled in about 15 years.