6A pharmaceutical company claims its painkiller tablet will start acting to reduce pain in 11 minutes or less, on average. To test this, scientists at the drug regulatory authority plan to carry out a hypothesis test using the hypotheses H0: =11 against Ha: > 11.

They take a random sample of n = 38 people. For each person they artificially induce a headache and use sophisticated equipment to record the time that it takes for the painkiller to start to have an effect on the person's nervous system.

The sample mean is 12.98 minutes and the sample standard deviation is 3.23 minutes.

Select the correcttest statistic(calculated to 3 decimal places) for this test from the list below.

This will be a t-test statistic because we are standardising the sample mean using an estimate for the standard error (based ons,the sample standard deviation).

a.

2.892

b.

3.779

c.

4.357

d.

3.490