17. A company wants to launch a new type of battery. Their past experience has indicated that the life of the new product is approximately normally distributed with a mean value of 150 hours and a standard deviation of 25 hours.

1. What percentage of the batteries will last over 140 hours?

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2. What percentage of the batteries will last below 125 hours?

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3. What percentage of the batteries will last between 145 and 155 hours?

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4. 90% of the batteries will last more than how many hours?

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(1) Manual Method

In order to evaluate the satisfactory level of a particular school service provided for students, a survey was conducted in schools for collecting students’ satisfactory ratings on the service provided in three years of 2003, 2004 and 2005. The rating scale ranges from 0 to 10, with 0 not satisfaction and 10 extreme satisfaction. Suppose the satisfactory levels follow a normal distribution. The survey data were collected and then processed by SPSS. The SPSS descriptive statistics are shown in below Table 1.

Table 1: Descriptive Statistics

	N	Mean	Std. Deviation	Variance
Satisfactory level in 2003	18	6.4389	1.48369	2.201
Satisfactory level in 2004	18	6.3889	.75994	.578
Satisfactory level in 2005	18	7.6167	1.38744	1.925
Valid N (listwise)	18

17. Set up a 95% confidence interval estimate for the average satisfactory level in 2003.

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17. Supposing the population standard deviation of satisfactory levels in 2003 is equal to 1, what sample size is required if the Margin of Error is ± 0.2 at 95% of confidence for the estimate of the average satisfactory level in 2003?

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17. Is there evidence that means satisfactory level in 2003 is different from 6 at α=0.05?

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17. Supposing the population variances of satisfactory in 2003 and 2005 are equal, is there evidence that means satisfactory level in 2003 is different from that in 2005 at α =0.05?

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17. Supposing the population variances of satisfactory in 2003 and 2004 are not equal, is there evidence that means satisfactory level in 2003 is different from that in 2004 at α =0.05?

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(2) SPSS Method

In order to study the consumers’ attitude and behavior in purchasing brand sports products towards to celebrity endorsement, an FYP project was conducted in ITC. Parts of the questionnaire and survey data are extracted for your following SPSS analysis. The data file is named as “Survey Data. sav” and the questionnaire file is named “Questionnaire.pdf”. Both files are available at Teams/Blackboard under the “SPSS Data” folder. Note: Appropriate supporting outputs of SPSS should be included in your answers.

17. Is there evidence that means the importance of Brand Reputation is different from 6 at α =0.05?

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17. Evaluate the difference of mean importance between Brand Expertise and Brand Believability at α =0.05.

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17. All the respondents can be classified into 4 groups according to their ages: 15-18, 19-22, 23-25, and 26 or above. Evaluate the difference of mean importance given by the 4 groups of respondents on Celebrity Endorsement at α =0.05.

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17. Evaluate the difference of mean importance given by the above 4 groups of respondents on Functional at α =0.05.

Answer rating: 100% (QA)

SOLUTION For the battery problem To find the percentage of batteries that will last over 140 hours we need to standardize the value using the zscore formula z 140 150 25 04 Using a standard normal dis... View the full answer