Home / 911.70-1,256.79-631.50

Finding the Fourth Proportional to 911.70, 1,256.79 and 631.50

Calculator

Solution

The fourth proportional to 911.70, 1,256.79 and 631.50 is: 870.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.70 : 1,256.79 = 631.50 : x
  2. Step 2: Convert to fraction form
    911.70/1,256.79 = 631.50/x
  3. Step 3: Cross multiply
    911.70x = 1,256.79 × 631.50
  4. Step 4: Simplify right side
    911.70x = 793,662.89
  5. Step 5: Solve for x
    x = 793,662.89/911.70
  6. Step 6: Final answer
    x = 870.53

Related Problems

Find fourth proportional to 455.85, 628.40 and 315.75
Half scale
Find fourth proportional to 1,823.40, 2,513.58 and 1,263
Double scale
Find fourth proportional to 912.70, 1,258.17 and 632.50
Similar ratio
Find fourth proportional to 1,367.55, 1,885.19 and 947.25
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.