SOLUTION: 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 the

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Question 1083977: 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.
If 6% 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°
b. 1.39°
c. 1.56°
d. 1.26°
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Answer: Choice C) 1.56 degrees
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Explanation:

Use a standard normal table (z table), to locate the value 0.9400 or something close to it. The closest value in the table is 0.9406 which happens when z = 1.56 (see page 2; read the row 1.50 and the column 0.06)

This means

So the value z = 1.56 is the approximate critical z value that cuts off the bottom 94% from the top 6%