EBook Problems Estim Proportion - Revision history

Tdlee: Text replacement - "{{translate|pageName=http://wiki.stat.ucla.edu/socr/" to ""{{translate|pageName=http://wiki.socr.umich.edu/"

2020-03-03T18:48:22Z

Text replacement - "{{translate|pageName=http://wiki.stat.ucla.edu/socr/" to ""{{translate|pageName=http://wiki.socr.umich.edu/"

IvoDinov: typos

2011-03-11T01:04:12Z

typos

JayZzz at 19:45, 8 January 2009

2009-01-08T19:45:38Z

JayZzz at 07:19, 6 January 2009

2009-01-06T07:19:32Z

JayZzz at 01:00, 4 January 2009

2009-01-04T01:00:13Z

JayZzz at 23:47, 28 December 2008

2008-12-28T23:47:17Z

JayZzz at 02:18, 4 December 2008

2008-12-04T02:18:30Z

JayZzz at 20:56, 2 December 2008

2008-12-02T20:56:06Z

JayZzz at 20:38, 2 December 2008

2008-12-02T20:38:51Z

JayZzz: /* Problem 3 */

2008-11-28T21:28:12Z

‎Problem 3

← Older revision		Revision as of 18:48, 3 March 2020
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	* SOCR Home page: http://www.socr.ucla.edu		* SOCR Home page: http://www.socr.ucla.edu

−	{{translate\|pageName=http://wiki.~~stat~~.~~ucla~~.edu~~/socr~~/index.php/EBook_Problems_Estim_Proportion}}	+	"{{translate\|pageName=http://wiki.socr.umich.edu/index.php/EBook_Problems_Estim_Proportion}}

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 {{hidden|Answer|(c)}}
-===Problem 3===
+===Problem 4===
 A school district is worried that too many students are failing the high school exit exam. In a random sample of 60 high school students, there are 9 students who fail the exit exam. Administrators want to estimate the percentage of the students who fail with a margin of error of 3% and confidence level of 90%. How many students should they sample for a thorough investigation of the problem?
@@ Line 53: / Line 53: @@
 {{hidden|Answer|(c)}}
-===Problem 4===
+===Problem 5===
 A major newspaper wants to hire a polling agency to predict who will be the next governor. Agency A proposes to do the job with a random sample of 5000 voters at a cost of $50K (K = one thousand). Agency B proposes to do the job with a random sample of 7500 voters at a cost of $75K. Assume both agencies find the percentage of voters to be 40% and both use the normal model to calculate the 95% interval. Which agency will you hire? Hint: Compare the margin of error for the two agencies and the relative costs before making your decision.
@@ Line 67: / Line 67: @@
 {{hidden|Answer|(d)}}
-===Problem 5===
+===Problem 6===
 Suppose that the proportion of the adult population who jog is 0.15. What is the probability that the proportion of joggers in a random sample of size n =200 lies between 0.13 and 0.17?
@@ Line 81: / Line 81: @@
 {{hidden|Answer|(a)}}
-===Problem 6===
+===Problem 7===
 An investigator made a careful sample survey to estimate the prevalence of drug use at UCLA. Two assistants were stationed in front of Ackerman Union and instructed to interview all students who passed through at specified times. As it turned out, 39% of 369 students interviewed said they had used ecstasy at least once. Which of the following statements is correct?
@@ Line 95: / Line 95: @@
 {{hidden|Answer|(a)}}
-===Problem 7===
+===Problem 8===
 A survey is carried out at a university to estimate the percentage of undergraduates living at home during the current term. What is the population? What is the parameter?
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 {{hidden|Answer|(a)}}
-===Problem 8===
+===Problem 9===
 A recent Gallup Poll found that 23% of senior citizens exercise at least 3 times a week. The number 23% is
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 {{hidden|Answer|(d)}}
-===Problem 9===
+===Problem 10===
 Market researchers are interested in determining the true proportion of college students who use their ATM each week. Suppose they take 100 random samples of 40 college students and count those who use their ATM this week. Describe the distribution of proportions selected from each of these samples.
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 {{hidden|Answer|(b)}}
-===Problem 10===
+===Problem 11===
 Suppose that you and everyone else in a large stat class each selects a random sample of 50 Skittles candies, counts the greens, and computes the proportion of greens in their sample. Which of the following statements is true?
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 {{hidden|Answer|(a)}}
-===Problem 11===
+===Problem 12===
 Records at a large university (not UCLA, of course) indicate that 20% of all freshmen are placed on academic probation at the end of the first semester. A random sample of 100 freshmen found that 25% of them were placed on probation. The results of the sample:

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 :''(c) The proportion of green Skittles will always be within two deviations of our sample proportion.
 {{hidden|Answer|(a)}}
 <hr>
 * [[EBook | Back to Ebook]]

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 :''(d) The distribution of sample proportions is skewed to the right or high end.
 {{hidden|Answer|(b)}}
 <hr>
 * [[EBook | Back to Ebook]]

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 :''(d) An estimate of the percentage of all senior citizens who exercise in the population
 {{hidden|Answer|(d)}}
 <hr>
 * [[EBook | Back to Ebook]]

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 :''(d) I will hire A.
 {{hidden|Answer|(d)}}
 <hr>

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 :''(d) 233
 {{hidden|Answer|(c)}}
 <hr>

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 :''(d) The percentage of the American public who agree that we should spend more money on the mental health of the war veterans is 42%.''
 {{hidden|Answer|(c)}}
 <hr>
-* [[AP_Statistics_Curriculum_2007_Estim Proportion | Back to Ebook]]
+* [[EBook | Back to Ebook]]
 * SOCR Home page: http://www.socr.ucla.edu
-{{translate|pageName=http://wiki.stat.ucla.edu/socr/index.php?title=EBook_Problems_Estim_Proportion}}
+{{translate|pageName=http://wiki.stat.ucla.edu/socr/index.php/EBook_Problems_Estim_Proportion}}

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 ===Problem 3===
-The BBC news does a story and at one point the reporter says: A polling agency reports that the percentage of the American public who agree we should spend more money on the mental health of the war veterans is 42% +/- 3%
+The BBC news does a story and at one point the reporter says: "A polling agency reports that the percentage of the American public who agree we should spend more money on the mental health of the war veterans is 42% +/- 3%."
 *Choose one answer.