Chapter 1: Statistics
... Example: A machine used to fill 5-gallon buckets of driveway sealer has standard deviation 2.5 ounces. A random sample of 24 buckets showed a standard deviation of 2.9 ounces. Is there any evidence to suggest an increase in variability at the 0.05 level of significance? Assume the amount of drivewa ...
... Example: A machine used to fill 5-gallon buckets of driveway sealer has standard deviation 2.5 ounces. A random sample of 24 buckets showed a standard deviation of 2.9 ounces. Is there any evidence to suggest an increase in variability at the 0.05 level of significance? Assume the amount of drivewa ...
Lesson 8.1 Estimation µ when σ is Known Notes
... 1. We have a simple random sample of size n drawn from a population of x values. 2. The value of σ, the population standard deviation of x, is known 3. If the x distribution is normal, then our methods work for any sample size n. 4. If x has an unknown distribution then we require a sample size n ≥ ...
... 1. We have a simple random sample of size n drawn from a population of x values. 2. The value of σ, the population standard deviation of x, is known 3. If the x distribution is normal, then our methods work for any sample size n. 4. If x has an unknown distribution then we require a sample size n ≥ ...
Survey Tabulation: Stats 101
... the mean (average), median, standard deviation and standard error are often included on tables for analysis purposes. For example, it might be helpful to show the mean of a rating scale question and other numeric fields (i.e., age or income values). These measures summarize the key results in a few ...
... the mean (average), median, standard deviation and standard error are often included on tables for analysis purposes. For example, it might be helpful to show the mean of a rating scale question and other numeric fields (i.e., age or income values). These measures summarize the key results in a few ...
AP Statistics Chapter 11 - William H. Peacock, LCDR USN
... elementary school. Though there is a 25 MPH SCHOOL ZONE sign nearby, most drivers seem to go much faster than that, even when the warning sign flashes. The students randomly selected 20 flashing zone times during the school year, noted the speeds of the cars passing the school during the flashing zo ...
... elementary school. Though there is a 25 MPH SCHOOL ZONE sign nearby, most drivers seem to go much faster than that, even when the warning sign flashes. The students randomly selected 20 flashing zone times during the school year, noted the speeds of the cars passing the school during the flashing zo ...
Lecture 14
... There was some relationship between tests scores and the type of community in which the parents lived. For example, big-city children averaged 26 points on the tests, and the SD was 10 points. Rural children average 25 points with the same SD. Can the difference be explained as chance variation? Ass ...
... There was some relationship between tests scores and the type of community in which the parents lived. For example, big-city children averaged 26 points on the tests, and the SD was 10 points. Rural children average 25 points with the same SD. Can the difference be explained as chance variation? Ass ...
Just My Cup of t (test)
... In science, researchers are often looking to see if experimental group data are significantly different from control group data. (If the data are significantly different, the researchers may propose that their treatment, the independent variable, within the experimental group caused the observed dif ...
... In science, researchers are often looking to see if experimental group data are significantly different from control group data. (If the data are significantly different, the researchers may propose that their treatment, the independent variable, within the experimental group caused the observed dif ...
Normalizing data.
... 1 Overview We often want to compare scores or sets of scores obtained on different scales. For example, how do we compare a score of 85 in a cooking contest with a score of 100 on an I.Q. test? In order to do so, we need to “eliminate” the unit of measurement, this operation is called to normalize t ...
... 1 Overview We often want to compare scores or sets of scores obtained on different scales. For example, how do we compare a score of 85 in a cooking contest with a score of 100 on an I.Q. test? In order to do so, we need to “eliminate” the unit of measurement, this operation is called to normalize t ...
