MATH 2565 Lecture Notes - Confidence Interval, Statistical Parameter, Type I And Type Ii Errors
10 Jan 2013
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As the number of degrees of freedom increases, the centres of t-models do not change. The spread of t-models decreases as the number of degrees of freedom increases, and the shape of the distribution becomes closer to normal. The confidence interval is not about the individual students in the population: not correct. The confidence interval is not about individual students in the sample. In fact, we know exactly what these students spent, so there is no need to estimate: not correct. We know that the mean cost for students in this sample was : not correct. A confidence interval is not about other sample means: this is the correct interpretation of a confidence interval. Problem 23. 9 pulse rates. a)we are 95% confident the interval 70. 9 to 74. 5 beats per minute contains the true mean heart rate: the width of the interval is about 74. 5 70. 9 = 3. 6 beats per minute.
