CarMD reports that the cost of repairing a hybrid vehicle is falling even while typical repairs on conventional vehicles are getting more expensive. One of the most common hybrid repairs, replacing the hybrid inverter assembly, had a mean repair cost of $1,357 in 2014. (Data extracted from 2015 CarMD Vehicle Health Index, available at bitly.com/1Gd3tjg.) Industry experts suspect that the cost will continue to decrease given the increase in the number of technicians who have gained expertise on fixing gas- electric engines in recent months. Suppose a sample of 100 hybrid inverter assembly repairs completed in the last month was selected. The sample mean repair cost was $1,280 with the sample standard deviation of $300. a. Is there evidence that the population mean repair cost is less than $1,357? (Use a 0.05 level of significance.) b. Determine the p-value and interpret its meaning. Need assistance to understand calculation of p-value
CarMD reports that the cost of repairing a hybrid vehicle is falling even while typical repairs on conventional vehicles are getting more expensive. One of the most common hybrid repairs, replacing the hybrid inverter assembly, had a
Need assistance to understand calculation of p-value
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