1. Lightbulbs made by Betterbulbs last, on average, 1000 hours with a standard deviation of 0.5 hours. a) What percent of their bulbs will burn more than 1000.09 hours, on average? b) If you tested 100 bulbs randomly, find the probability that the average number of hours these burned exceeded 1000.09 hours.

Suppose that an airline uses a seat width of 16.7 in. Assume that men have hip breadths that are normally distributed with a mean of 14.2 inches, and a standard deviation of 1in.  Find the probability that if an individual man is randomly selected that his hip breadths will be greater than 16.7 in.

The number of ants per acre in the forest is normally distributed with mean 42,000 and standard deviation 12,221. Let X = number of ants in a randomly selected acre of the forest. Round all answers to 4 decimal places where possible.   b. Find the probability that a randomly selected acre in the forest has fewer than 32,793 ants. c. Find the probability that a randomly selected acre has between 46,676 and 51,692 ants. d. Find the first quartile. ?                    ants (round your answer to a whole number) PLEASE ANSWER THE 3 SUBS B, C AND D

1. The average number of acres burned by forest and range fires in a large New Mexico county is 4,255 acres per year, with a standard deviation of 744 acres. The distribution of the number of acres burned is normal. a.) What is the probability that between 2,540 and 4,190 acres will be burned in any given year? b.)What number of burnt acres corresponds to the 38th percentile?

In the country of United States of Heightlandia, the height measurements of ten-year-old children are approximately normally distributed with a mean of 53.3 inches, and standard deviation of 2.2 inches.What is the probability that the height of a randomly chosen child is between 51.3 and 57.1 inches? Do not round until you get your your final answer, and then round to 3 decimal places.Answer=___________ (Round your answer to 3 decimal places.)

Most people think that the​ "normal" adult body temperature is 98.6°F. In a more recent​ study, researchers reported that a more accurate figure may be 98.1°F. ​Furthermore, the standard deviation appeared to be around 0.7°F. Assume that a Normal model is appropriate.   b) What fraction of people would be expected to have body temperatures above 98.6°​F?

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Suppose that you have a four-sided die that is equally weighted (i.e. equal chance of any of the four sides landing face up). The four values on the die are [12.5968, 2, -2 and -12.5968] . What is the standard deviation using the conceptual definition? That is, what is the average distance from the data points to the mean?   A. 5.34   B. 4.09   C. 2.58   D. 7.29