study conducted across the US with n = 545 children found that on average kids are getting glasses at 5.5 years old. If the standard deviation is known to be .75 years.

Using your TI-84:

State a 95% confidence iinterval for the mean age of children getting corrective lenses (copy the wording from the problem to fill in the blanks as needed):

I am % confident that is between and .

Another study in Europe found that children there weren't getting glasses as early. They conducted a large decade long study from 2000 to 2015 and found that the average age was =6.2 years (we can use longitudinal data as population data).

Is there statistical evidence that children in the US are getting glasses sooner than European children at the .05 level?

Set up the hypothesis -

you can copy and paste any symbols from here:

Do not use spaces between your symbols

Ho: Ha:

Using your TI-84: Compute the test statistic: and p-value =

and state your conclusion (again, i encourage you to copy and paste the wording from the problem above):

There (is/is not) statistically significant evidence at the level that.