Home / 971.70-1,340.22-688

Finding the Fourth Proportional to 971.70, 1,340.22 and 688

Calculator

Solution

The fourth proportional to 971.70, 1,340.22 and 688 is: 948.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.70 : 1,340.22 = 688 : x
  2. Step 2: Convert to fraction form
    971.70/1,340.22 = 688/x
  3. Step 3: Cross multiply
    971.70x = 1,340.22 × 688
  4. Step 4: Simplify right side
    971.70x = 922,071.36
  5. Step 5: Solve for x
    x = 922,071.36/971.70
  6. Step 6: Final answer
    x = 948.93

Related Problems

Find fourth proportional to 485.85, 670.11 and 344
Half scale
Find fourth proportional to 1,943.40, 2,680.44 and 1,376
Double scale
Find fourth proportional to 972.70, 1,341.60 and 689
Similar ratio
Find fourth proportional to 1,457.55, 2,010.33 and 1,032
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.