The formula used to calculate a large-sample confidence interval for p is
What is the appropriate z critical value for each of the following confidence levels?
- a. 95%
- b. 90%
- c. 80%
- d. 99%
- e. 85%
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Introduction to Statistics and Data Analysis
- The distribution of study times for first-year students follows a normal distribution with a standard deviation = 45 minutes. Suppose a sample of 486 students found that the mean study for these students was =180 minutes per week. Use this to find a 95% confidence interval to estimate the mean study time for all students. We are 95% confident that the mean study time for first-year students is betweenarrow_forwardThe number of cell phones per 100 residents in countries in Europe is given in table #9.3.9 for the year 2010. The number of cell phones per 100 residents in countries of the Americas is given in table #9.3.10 also for the year 2010 ("Population reference bureau," 2013). Find the 98% confidence interval for the different in mean number of cell phones per 100 residents in Europe and the Americas. (Show all work) Table #9.3.9: Number of Cell Phones per 100 Residents in Europe 100 100 76 100 130 75 84 112 112 84 138 133 118 134 126 126 188 129 93 64 128 124 124 122 109 121 127 152 96 96 63 99 95 151 147 123 123 95 67 67 118 125 110 110 115 140 115 141 77 98 98 102 102 112 118 118 54 54 23 121 126 47 Table #9.3.10: Number of Cell Phones per 100 Residents in the Americas 158 117 106 159 53 50 78 66 88 92 42 3…arrow_forwardWhat is the positive t-value for a confidence interval for the population mean with a sample size of 30 at a 90% confidence level? Express with 3 decimalsarrow_forward
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- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill