If the Census wants to increase its level of confidence and keep the error bound the same by taking another survey, what changes should it make?
If the Census wants to increase its level of confidence and keep the error bound the same by taking another survey, than they should increase the sample size .
The sample mean is minutes. There is a known standard deviation of minutes. The population distribution is assumed to be normal.
A tighter confidence interval with a smaller margin of error will arise from a bigger sample size or lower variability. A wider confidence interval with a larger margin of error will arise from a smaller sample size or higher variability.
The Ice Chalet offers dozens of different beginning iceskating classes. All of the class names are put into a bucket. The 5 P.M., Monday night, ages 8 to 12, beginning ice-skating class was picked. In that class were 64 girls and 16 boys. Suppose that we are interested in the true proportion of girls, ages 8 to 12, in all beginning ice-skating classes at the Ice Chalet. Assume that the children in the selected class are a random sample of the population.
What is being counted?
You do a study of hypnotherapy to determine how effective it is in increasing the number of hours of sleep subjects get each night. You measure hours of sleep for subjects with the following results. Construct a % confidence interval for the mean number of hours slept for the population (assumed normal) from which you took the data. ; ; ; ; ; ; ; ; ; ; ;
The mean age for all Foothill College students for a recent Fall term was . The population standard deviation has been pretty consistent at . Suppose that twenty-five Winter students were randomly selected. The mean age for the sample was . We are interested in the true mean age for Winter Foothill College students. Let the age of a Winter Foothill College student.
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