How to Find a Missing Value in a Data Set Using the Average (GED Math)

Understanding the Average Formula

• 🎯 The average (mean) of a data set is calculated by dividing the sum of all numbers by the count of numbers in the set.
• 💡 In this problem, we are given a data set with a missing value, represented by 'Z', and its average.

Setting Up the Equation

• 📊 The given data set is 26, 42, Z, 34, 68, and 20, with an average of 40.
• ➕ The sum of these six numbers is 26 + 42 + Z + 34 + 68 + 20.
• ➗ The equation for the average is (26 + 42 + Z + 34 + 68 + 20) / 6 = 40.

Solving for the Missing Value (Z)

• 🔢 To isolate Z, first multiply both sides of the equation by 6: 6 * 40 = 240.
• ➕ Combine the known numbers in the data set: 26 + 42 + 34 + 68 + 20 = 190.
• 🧩 The equation simplifies to 240 = 190 + Z.
• ➖ Subtract 190 from both sides to find Z: Z = 240 - 190.
• ✅ The missing value, Z, is 50.