Question

Difficulty: MediumDescriptive Statistics and Data Representations

A track and field athlete recorded the following distances, in meters, for 5 long jump trials during a training session: 5.85.8, 6.26.2, 5.55.5, 6.56.5, and 6.06.0. The coach requires the athlete to achieve an overall mean distance of exactly 6.16.1 meters across 66 trials. What distance, in meters, must the athlete jump on the 6th trial to reach this target mean?

  1. A
    0.50.5
  2. B
    1.11.1
  3. C
    6.16.1
  4. 6.66.6Answer
  5. E
    7.27.2

Answer

6.66.6 meters
To achieve a mean of 6.16.1 meters across 66 trials, the total combined distance must be 6×6.1=36.66 \times 6.1 = 36.6 meters. Summing the first 5 jump distances gives 5.8+6.2+5.5+6.5+6.0=30.05.8 + 6.2 + 5.5 + 6.5 + 6.0 = 30.0 meters. Subtracting this sum from the required total (36.630.036.6 - 30.0) yields 6.66.6 meters for the 6th trial.

Step-by-Step Solution

1
Calculate the total distance of the first 5 trials.
5.8+6.2+5.5+6.5+6.0=30.05.8 + 6.2 + 5.5 + 6.5 + 6.0 = 30.0 meters
Finding the total distance currently accumulated is necessary to determine how much more is needed.
2
Calculate the total required distance for all 6 trials to achieve the target mean.
6×6.1=36.66 \times 6.1 = 36.6 meters
The formula for the mean is Mean=Total SumNumber of Trials\text{Mean} = \frac{\text{Total Sum}}{\text{Number of Trials}}, so Total Sum=Mean×Number of Trials\text{Total Sum} = \text{Mean} \times \text{Number of Trials}.
3
Subtract the current sum from the required total sum to find the required 6th jump distance.
36.630.0=6.636.6 - 30.0 = 6.6 meters
The difference between the required total distance and the current distance gives the necessary score on the final trial.

Key Concept

Target Mean with Missing Value
Estimated Time:1m 0s
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