A calling agency has data showing that the average response time is 5.6 minutes with a standard deviation of 1.8.The manager wants to know how much time is required for 75% of all calls to be handled(in other words,the value below which 3/4 of response times fall). First find the Z-score and then use the Z-score formula,but solve for X given a particular value of Z)

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Confidence Intervals

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calculated is present here only.