The Precision Scientific Instrument Company manufactures thermometers that are supposed to give readings of 0°C at the freezing point of water. Tests on a large sample of these thermometers reveal that at the freezing
Point of water, some give readings below 0°C (denoted by negative numbers) and some give readings above
0°C (denoted by positive numbers). Assume that the mean reading is 0°C and the standard deviation of the
Readings is 1.00°C. Also assume that the frequency distribution of errors closely resembles the normal
Distribution. A thermometer is randomly selected and tested. A quality control analyst wants to examine
Thermometers that give readings in the bottom 4%. Find the temperature reading that separates the bottom 4%
From the others.
A) -1.48°
B) -1.75°
C) -1.89°
D) -1.63°

Question

Quizplus · Accepted Answer

The bottom 4% of a normal distribution corresponds to a z-score of approximately -1.75. Given the mean is 0°C and the standard deviation is 1°C, the temperature reading that separates the bottom 4% is -1.75°C.

The Precision Scientific Instrument Company Manufactures Thermometers That Are Supposed