Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. many complain that the time devoted to previews is too long (the wall street journal, october 12, 2012). a preliminary sample conducted by the wall street journal showed that the standard deviation of the amount of time devoted to previews was 4 minutes. use that as a planning value for the standard deviation in answering the following questions. a. if we want to estimate the population mean time for previews at movie theaters with a margin of error of 75 seconds, what sample size should be used? assume 95% confidence. b. if we want to estimate the population mean time for previews at movie theaters with a margin of error of 1 minute, what sample size should be used? assume 95% confidence.

region b will make the inequalities y < 2x + 1 and y > -x - 2 true ⇒ answer a

step-by-step explanation:

* lets study the graph and the inequality to solve the question

- the inequality y > -x - 2

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = -2 that means the line intersect the y-axis at point (0 , -2)

∵ the sign of the inequality is >

∴ we shad the part over the line

  region a and b

- the inequality y < 2x + 1

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = 1 that means the line intersect the y-axis at point (0 , 1)

∵ the sign of the inequality is <

∴ we shad the part under the line

  region b and c

∵ the common region between the two lines is region b

∴ region b will make the inequalities y < 2x + 1 and y > -x - 2 true

66.666666667%

step-by-step explanation:

divide 150 by 100

divide 100 by 1.5

there you go!

decreased by 33.333333334%

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step-by-step explanation: