When do creative people get their best ideas? USA Today did a survey of 966 inventors (who hold U.S. patents) and obtained the following information.

Time of Day When Best Ideas Occur
Time Number of Inventors
6 A.M.-12 noon 271
12 noon-6 P.M. 123
6 P.M.-12 midnight 327
12 midnight-6 A.M. 245

Required:
a. Assuming that the time interval includes the left limit and all the times up to but not including the right limit, estimate the probability that an inventor has a best idea during each time interval: from 6 A.M. to 12 noon, from 12 noon to 6 P.M., from 6 P.M. to 12 midnight, from 12 midnight to 6 A.M.
b. Do the probabilities add up to 1? Why should they?

Respuesta :

Answer:

a.

0.2805 = 28.05% probability that an inventor has a best idea from 6 A.M. to 12 noon.

0.1273 = 12.73% probability that an inventor has a best idea from 12 noon to 6 P.M.

0.3385 = 33.85% probability that an inventor has a best idea from 6 P.M. to 12 midnight.

0.2536 = 25.36% probability that an inventor has a best idea from 12 midnight to 6 A.M.

b. They do, as the the sum of the probabilities of all possible outcomes should be 1, as is in this question.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the total outcomes.

We have:

A total of 966 inventors.

Question a:

6 A.M. to 12 noon

271 out of 966, so:

[tex]p = \frac{271}{966} = 0.2805[/tex]

0.2805 = 28.05% probability that an inventor has a best idea from 6 A.M. to 12 noon.

12 noon to 6 P.M.

123 out of 966, so:

[tex]p = \frac{123}{966} = 0.1273[/tex]

0.1273 = 12.73% probability that an inventor has a best idea from 12 noon to 6 P.M.

6 P.M. to 12 midnight

327 out of 966, so:

[tex]p = \frac{327}{966} = 0.3385[/tex]

0.3385 = 33.85% probability that an inventor has a best idea from 6 P.M. to 12 midnight.

12 midnight to 6 A.M.

245 out of 966. So

[tex]p = \frac{245}{966} = 0.2536[/tex]

0.2536 = 25.36% probability that an inventor has a best idea from 12 midnight to 6 A.M.

b. Do the probabilities add up to 1? Why should they?

0.2805 + 0.1273 + 0.3385 + 0.2536 = 1

They do, as the the sum of the probabilities of all possible outcomes should be 1, as is in this question.