To use this function, choose .
Stores the product of the first i rows of the input column in the ith 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).
PARP(number)
For number, specify the input column.
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.