Reference no: EM132177432
Consider the following two scenarios:
The mean height of coastal redwood trees is known to be 200 feet. In order to test whether a community of coastal trees were growing to be healthy in a park with high rates of tourism, a random sample of 20 trees were measured. It was found that for the 20 sampled trees, the average height was 197.5 feet with a standard deviation of 6.7. It is known that tree heights follow a normal distribution
The mean height of coastal redwood trees is known to be 200 feet. In order to test whether a community of coastal trees were growing to be healthy in a park with high rates of tourism, a random sample of 20 trees were measured. It was found that for the 20 sampled trees, the average height was 197.5 feet. It is known that tree heights follow a normal distribution with a standard deviation of 7.
Which of the following is correct:
A) In the second scenario, the population standard deviation is not known, therefore a z-test should be used.
B) In the second scenario, the population standard deviation is known, therefore a t-test should be used.
C) In the second scenario, the sample standard deviation is known, therefore a z-test should be used.
D) In the second scenario, the population standard deviation is known, therefore a z-test should be used.