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.
-If 7% of the thermometers are rejected because they have readings that are too high, but all other thermometers are acceptable, find the temperature that separates the rejected thermometers from
The others.
A) $1.48 ^ { \circ }$
B) $1.26 ^ { \circ }$
C) $1.39 ^ { \circ }$
D) $1.45 ^ { \circ }$

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.
-If 7% of the thermometers are rejected because they have readings that are too high, but all other thermometers are acceptable, find the temperature that separates the rejected thermometers from
The others. 
A) $1.48 ^ { \circ }$
B) $1.26 ^ { \circ }$
C) $1.39 ^ { \circ }$
D) $1.45 ^ { \circ }$

Quizplus · Accepted Answer

The temperature that separates the top 7% of the thermometers from the rest corresponds to the 93rd percentile of a standard normal distribution. Using a standard normal distribution table or calculator, the z-score for the 93rd percentile is approximately 1.48. Therefore, the temperature reading is 1.48°C.

The Precision Scientific Instrument Company Manufactures Thermometers That Are Supposed 1.48∘1.48 ^ { \circ }1.48∘

The Precision Scientific Instrument Company Manufactures Thermometers That Are Supposed $1.48 ^ { \circ }$