In: Statistics and Probability
You have a company with 300 employees. Every year they have to
go through a mandatory training which requires them to watch
company made videos. You want to test if the employees will pay
more attention to the videos if they include popular music (top 50
hits) or classical music. You select 40 employees to take part in a
study where they watch the videos alone in a room and someone
watching from a webcam counts how many times the employee looked
away from the screen (you call this 'Distractions'). Half of the
employees watch the videos with popular music and the other half
watch with classical music. Use Popular music as group 1 and
Classical music as group 2. The first 5 rows of the data are shown
here.
a. What is the sample?
b. What is the population of interest?
c. What is the parameter you are interested in? ---
x1-x2 μ x μ1-μ2
There is also a summary of the data:
Group | Mean | Standard deviation |
Popular | 27.9 | 8.2 |
Classical | 36.2 | 9.5 |
(For the numerical answers below, use 2 decimal places.)
d. The point estimate is:
e. The standard error is:
f. The 95% confidence interval goes from
to
g. Which group had more distractions in the sample? ---
Classical They were equal Popular
h. Would you say that there is a difference between the groups at
the population level? Explain why or why not. If you say there is a
difference explain which group has more distractions?