City Power & Light produces voltage-regulating equipment in New York and ships the equipment to Chicago. A voltage regulator is considered acceptable if it can hold a voltage of 25 to 75 volts. The voltage held by each unit is measured in New York before the unit is shipped. The voltage is measured again when the unit arrives in Chicago. A sample of voltage measurements from each city is given in the file Citypower.xlsx.

Using descriptive statistics, comment on what you have learned about the voltage held by units before and after shipment.

What percentage of units is acceptable before and after shipping?

Do you have any suggestions about how to improve the quality of City Power & Light’s regulators?

Ten percent of all New York regulators have a voltage exceeding what value?

Five percent of all New York regulators have a voltage less than or equal to what value?