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. Find the temperature reading corresponding to the given information.
-P(-0.73

Question

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. Find the temperature reading corresponding to the given information.
-P(-0.73 < Z < 2.27)
A)0.4884
B)0.7557
C)1.54
D)0.2211

Quizplus · Accepted Answer

The probability P(-0.73 < Z < 2.27) corresponds to the area under the standard normal curve between Z = -0.73 and Z = 2.27. Using a standard normal distribution table or calculator, the area (probability) between these Z-scores is approximately 0.7557.

The Precision Scientific Instrument Company Manufactures Thermometers That Are Supposed