Question

a contractor claims that she finishes a job on - time 90% of the time. last month, she only completed 7 out of 10 jobs on - time. to see if this is surprisingly low, a simulation was conducted 100 times under the assumption that she really does complete 90% of her jobs on time. the dot - plot contains 100 trials of this simulation. based on this dot - plot and the sample of last months on - time completions, which conclusion can be drawn? the dot - plot does not provide convincing evidence that her true, on - time completion rate is less than 90% because 7 or fewer on - time completions happened 19% of the time in the simulation. if we used a larger sample size of 40 jobs, the simulated dot - plot would be different; therefore, we cannot draw a conclusion.

Explanation:

Step1: Analyze the given statement

The contractor claims 90% on - time completion rate. In last month, 7 out of 10 jobs were on - time. Simulation was done 100 times and 7 or fewer on - time completions happened 19% of the time.

Step2: Evaluate the conclusion

A 19% chance of getting 7 or fewer on - time completions in the simulation means that getting 7 out of 10 on - time completions is not extremely rare under the assumption of a 90% on - time completion rate.

Answer:

The dotplot does not provide convincing evidence that her true, on - time completion rate is less than 90% because 7 or fewer on - time completions happened 19% of the time in the simulation.