Neco 2023 Data Processing Question 42

A spreadsheet records monthly sales (units) of four products over six months as follows:\n\nProduct A: 120, 135, 150, 165, 180, 195\nProduct B: 200, 190, 210, 205, 215, 220\nProduct C: 80, 85, 90, 95, 100, 105\nProduct D: 150, 155, 160, 165, 170, 175\n\nUnit prices are: A = \(\text{₦}50\), B = \(\text{₦}40\), C = \(\text{₦}60\), D = \(\text{₦}55\). The total revenue for month \(i\) is the sum of each product's units sold multiplied by its unit price. The month‑to‑month growth rate is \(g_i = \frac{R_i - R_{i-1}}{R_{i-1}}\) for \(i = 2,\dots,6\). After adjusting each growth rate for a constant monthly inflation of 2%, the adjusted growth is \(a_i = g_i - 0.02\). Find the median of the five adjusted growth rates \(a_2, a_3, a_4, a_5, a_6\), expressed as a decimal rounded to three decimal places.