Cacti have been used for medicinal purposes tor centuries. In the last 50 years,
ID: 3176390 • Letter: C
Question
Cacti have been used for medicinal purposes tor centuries. In the last 50 years, cacti have also because popular landscape plants. Consequently, mature cacti have been dug up in the desert for sale in plant nurseries. Researchers interested in the age of a certain medicinal cacti found in the Arizona desert 50 years ago, the average age of this cacti was 171 years. The researchers want to know if the average age of al cacti (of this type) living in an Arizonan national forest has decreased. They take a random sample of 64 cacti found in this Arizona national forest. Below are the charts and plots of their data. Set the population standard deviation = 49. Are the conditions met to calculate a 95% Cl for the mean? Yes because the sample size over 30 and the subjects were randomly selected. Yes because the subjects were randomly selected, the sample size is over 30 and there are no extreme outliers no If you answered yes to part (a), then it is appropriate to calculate a 95% Cl for the mean. Find this interval. Give your answer to the nearest integer. (123, 147) Which of the following would be the best interpretation of the interval you calculated in part (b)? We are 95% comment that the average age of all cacti in this national forest is 135 years. We are 95% confident that 135 is one of the values n the above confidence interval. We are 95% confident that the average age of all cacti living in this national forest is one of the values in the above confidence interval. There is a 95% probability that the average age of al cacti in this national forest is one of the values of the above confidence intervalExplanation / Answer
Result:
a).
Yes, because the subjects were randomly selected, the sample size is over 30 and there are no extreme outliers.
( include that there is no outlier assumption)
c).
we are 95% confident that the average age of all each living in this national forest is one of the values in the above confidence interval.
95% confident means we are 95% confident that population mean will fall in the interval.