Confidence intervals (CI) are one of the simpler forms of inferential statistics. What does the CI represent? And why does our knowledge of the Central Limit Theorem (CLT) and the empirical rule let us understand why the ...
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Five houses in a row are each to be painted with one of the colors? red, blue,? green, and yellow. In how many different ways can the houses be painted so that no two adjacent houses are of the same? color? Answer is 324 ...
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From a random sample of 41 teens, it is found that on average they spend 31.8 hours each week online with a standard deviation of 3.65 hours. What is the 90% confidence interval for the amount of time they spend online e ...
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The probability that a shot will hit the target is 0.02. Successive shots are independent of each other. What is the probability that at least one out of four shots will hit the target?
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Determine the sample size needed to construct a 90?% confidence interval to estimate the average GPA for the student population at a college with a margin of error equal to 0.5. Assume the standard deviation of the GPA f ...
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The critical boundaries (Zcrit) for a hypothesis test are z = +1.96 and z = -1.96. If the z-score for the sample data is z = -1.90, then what is the correct statistical decision? A) Reject H1 B) Fail to reject H1 C) Re ...
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A researcher is working on a study that examines the wellbeing of older adults. She has an interest in finding if there is a difference in life satisfaction scores (measured on a multi-item Likert scale) by ethnicity (Af ...
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A rainstorm in Portland, Oregon, wiped out the electricity in 10% of the households in the city. Suppose that a random sample of 70 Portland households is taken after the rainstorm. Estimate the number of households in t ...
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What are the minimum, first quartile, median, third quartile, maximum, interquartile range, and range of the data set below? Make a box-and- whisker plot. 25, 25, 30, 35, 45, 45, 50, 55, 60, 60
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Consider the distribution of 17 numbers: 6,9,11,19,23,27,29,36,41,43,47,50,51,55,58,63,67 A distribution of medical data is Normal with Mean of 40 and Standard Deviation of 10; that is N(40,10) a. Betty's score is 5.17. ...
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