Question

if z is a standard normal variable, find the probability.

1. the probability that z lies between -2.41 and 0

a) 0.0948 b) 0.5080 c) 0.4910 d) 0.4920

1. the probability that z lies between -1.10 and -0.36

a) 0.2237 b) 0.4951 c) 0.2239 d) -0.2237

1. the probability that z lies between -0.55 and 0.55

a) -0.9000 b) 0.9000 c) 0.4176 d) -0.4176
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.

1. 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) 1.45° b) 1.48° c) 1.26° d) 1.39°

1. if 7% of the thermometers are rejected because they have readings that are too low, but all other thermometers are acceptable, find the temperature that separates the rejected thermometers from the others.

a) -1.39° b) -1.48° c) -1.26° d) -1.53°

1. a quality control analyst wants to examine thermometers that give readings in the bottom 7%. find the reading that separates the bottom 7% from the others.

a) -1.48° b) -1.75° c) -1.63° d) -1.89°
find the indicated value.

1. z0.36

a) 1.76 b) 0.45 c) 1.60 d) 0.36

Explanation:

Answer:

(11) C. 0.4910
(12) A. 0.2237
(13) C. 0.4176
(14) B. 1.48°
(15) A. -1.39°
(16) B. -1.75°
(17) D. 0.36