To try to determine whether the composition of the earth’s atmosphere has changed over time, scientists can examine the gas in bubbles trapped inside ancient amber. (that’s the plot of jurassic park.) assume that the following 9 measures are a random sample from the late cretaceous era (75 to 95 million years ago). the data represent the percent of nitrogen in each sample.

63.4 65.0 64.4 63.3 54.8 64.5 60.8 49.1 51.0

you asked to conduct a hypothesis test to determine whether the mean is less than 61.

1. conduct a hypothesis test using a 95% confidence interval.

a. what value for t will you use?

b. what is the sample mean?

c. what is the sample standard deviation?

d. what is the standard error?

e. calculate the confidence interval.

f. what conclusion will you draw about the null hypothesis and why.