EBook Problems Hypothesis Basics - Revision history

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

JayZzz at 06:43, 31 December 2008

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JayZzz at 05:02, 31 December 2008

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JayZzz at 04:32, 31 December 2008

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JayZzz at 01:53, 31 December 2008

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JayZzz at 21:47, 30 December 2008

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← Older revision		Revision as of 18:11, 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_Hypothesis_Basics}}	+	"{{translate\|pageName=http://wiki.socr.umich.edu/index.php/EBook_Problems_Hypothesis_Basics}}

← Older revision		Revision as of 06:43, 31 December 2008
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	:''(d) The t-value		:''(d) The t-value
		+	{{hidden\|Answer\|(b)}}
		+
		+	===Problem 22===
		+	When conducting a formal hypothesis test, there are different errors that may be made, depending on your decision. One decision is to reject the null hypothesis. If you falsely reject the null hypothesis, what type of error has been made?
		+
		+	*Choose one answer.
		+
		+	:''(a) Type II error
		+
		+	:''(b) Type I Error
		+
		+	:''(c) No error was made
		+
		+	:''(d) Critical Error
	{{hidden\|Answer\|(b)}}		{{hidden\|Answer\|(b)}}

← Older revision		Revision as of 05:07, 31 December 2008
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	:''(d) Yes, the p-value is less than 0.05		:''(d) Yes, the p-value is less than 0.05
	{{hidden\|Answer\|(d)}}		{{hidden\|Answer\|(d)}}
		+
		+	===Problem 21===
		+	When you set the significance level for a hypothesis test, what are you controlling for?
		+
		+	*Choose one answer.
		+
		+	:''(a) Type II error
		+
		+	:''(b) Type I error
		+
		+	:''(c) The critical value
		+
		+	:''(d) The t-value
		+	{{hidden\|Answer\|(b)}}

← Older revision		Revision as of 05:02, 31 December 2008
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	:''(d) Yes, because the z is 0.07		:''(d) Yes, because the z is 0.07
	{{hidden\|Answer\|(c)}}		{{hidden\|Answer\|(c)}}
		+
		+	===Problem 20===
		+	When a roulette wheel is perfectly balanced, in the long run red numbers should turn up 18 times in 38 spins. To test its wheel, one casino records the results of 3,800 plays, finding 1,000 red numbers. Based on how a roulette wheel is supposed to work, is that too few reds? Test at the 0.05 level.
		+
		+	*Choose one answer.
		+
		+	:''(a) No, because the p-value is less than 0.05
		+
		+	:''(b) No, because the p-value is bigger than 0.05
		+
		+	:''(c) Yes, the p-value is more than 0.05
		+
		+	:''(d) Yes, the p-value is less than 0.05
		+	{{hidden\|Answer\|(d)}}

← Older revision		Revision as of 04:32, 31 December 2008
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	:''(c) A two-sample proportion test is appropriate because the sample size is less than 10% the population size.		:''(c) A two-sample proportion test is appropriate because the sample size is less than 10% the population size.
	{{hidden\|Answer\|(b)}}		{{hidden\|Answer\|(b)}}
		+
		+	===Problem 18===
		+	A company is sued for job discrimination because only 19% of the newly hired candidates were minorites when 27% of all applicants were minorities. The lawyers will perform a hypothesis test to test whether the company's hiring practices are discriminatory. How will the power of the test compare if the test is done at the 5% level of significance as opposed to the 1% level of significance?
		+
		+	*Choose one answer.
		+
		+	:''(a) The power depends on the sample size and will therefore be the same at either level
		+
		+	:''(b) the power will be less at the 5% level than at the 1% level
		+
		+	:''(c) The power will be greater at the 5% level than at the 1% level
		+
		+	:''(d) The power depends on the difference between the true percentage of minority applicants and will therefore be the same at both significance levels
		+	{{hidden\|Answer\|(c)}}
		+
		+	===Problem 19===
		+	A manufacturer of automobiles purchases machine bolts from a supplier who claims that no more than 5% of his bolts are defective. The manufacturer suspects that this claim is false. From a random sample of 400 bolts, the manufacturer found that 28 are defective. Is there suficient evidence to reject the supplier's claim?
		+
		+	*Choose one answer.
		+
		+	:''(a) No, because the z is 0.07
		+
		+	:''(b) No, because the z is 1.851
		+
		+	:''(c) Yes, because the z is 1.851
		+
		+	:''(d) Yes, because the z is 0.07
		+	{{hidden\|Answer\|(c)}}

← Older revision		Revision as of 04:23, 31 December 2008
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	:''(d) Ho: p=0.38; Ha: p < 0.38		:''(d) Ho: p=0.38; Ha: p < 0.38
	{{hidden\|Answer\|(a)}}		{{hidden\|Answer\|(a)}}
		+
		+	===Problem 17===
		+	A team of sociologists is investigating attitudes towards religion. In particular, they wish to examine differences in attitudes between the genders. They take a random sample of 400 married couples, and ask both people in the couple: "Do you believe in a literal heaven and hell?". About 55% of the women and 54% of the men said that they did believe. The sociologists wish to perform a hypothesis test to test whether the percent of men who believe in a literal heaven and hell in the population is the same as the percent of women. Which of the following statements is true?
		+
		+	*Choose one answer.
		+
		+	:''(a) You should not perform a two-sample proportion test because the sample size is not sufficient.
		+
		+	:''(b) You should not perform a two-sample proportion test because the samples are not independent.
		+
		+	:''(c) A two-sample proportion test is appropriate because the sample size is less than 10% the population size.
		+	{{hidden\|Answer\|(b)}}

← Older revision		Revision as of 01:53, 31 December 2008
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	:''(d) Ho: p=0.6; Ha: p <0.6		:''(d) Ho: p=0.6; Ha: p <0.6
		+	{{hidden\|Answer\|(a)}}
		+
		+	===Problem 16===
		+	An experiment compares the taste of instant versus fresh-brewed coffee. Each subject tastes two unmarked cups of coffee in random order, one of each type, and states which he or she prefers. Of the 300 subjects who participate in the study, 114 prefer the instant coffee. Is there statistically significant evidence in the sample to support the suspicion that a majority of people prefer the taste of fresh-brewed coffee? Write the null and the alternative hypotheses for this test.
		+
		+	*Choose one answer.
		+
		+	:''(a) Ho: p=0.5; Ha: p < 0.5
		+
		+	:''(b) Ho: p=0.5; Ha: p>0.5
		+
		+	:''(c) Ho: p =0.6; Ha: p <0.6
		+
		+	:''(d) Ho: p=0.38; Ha: p < 0.38
	{{hidden\|Answer\|(a)}}		{{hidden\|Answer\|(a)}}

← Older revision		Revision as of 01:26, 31 December 2008
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	:''(d) It makes a type II error if it stops working with the tutoring agency when the standardized math scores have actually gone up at most 10%.		:''(d) It makes a type II error if it stops working with the tutoring agency when the standardized math scores have actually gone up at most 10%.
	{{hidden\|Answer\|(b)}}		{{hidden\|Answer\|(b)}}
		+
		+	===Problem 15===
		+	The standard medication for a certain disease is effective in 60% of all cases. A pharmaceutical company believes that its new drug is more effective than the standard treatment. Formulate the null and the alternative hypotheses to test whether there is statistical evidence to support the new drug.
		+
		+	*Choose one answer.
		+
		+	:''(a) Ho: p=0.6; Ha: p>0.6
		+
		+	:''(b) Can't be determined without knowing the sample
		+
		+	:''(c) Ho: p<0.6; Ha: p=0.6
		+
		+	:''(d) Ho: p=0.6; Ha: p <0.6
		+	{{hidden\|Answer\|(a)}}

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 :''(c) The rates between adopted youth and non-adopted are different, but researchers conclude they are the same.
 {{hidden|Answer|(a)}}
 <hr>

@@ Line 185: / Line 185: @@
 :''(e) The 3 sample means are equal to each other
 {{hidden|Answer|(d)}}
 <hr>