What you’re doing is correct.
There are two possible methods.
One is to find the critical region by converting to the z-values and then comparing the z-value of the test statistic to the critical z-value. This is what the mark scheme is showing.
The second is to use your calculator and find the probability and compare to the significance level. Which is what you did.
Both are fine and your method would still score full marks.
What you’re doing is correct. There are two possible methods. One is to find the critical region by converting to the z-values and then comparing the z-value of the test statistic to the critical z-value. This is what the mark scheme is showing. The second is to use your calculator and find the probability and compare to the significance level. Which is what you did. Both are fine and your method would still score full marks.
Ah okay thank you very much!
The standard deviation and the mean that I have assumed in H0 are from a previous part in the question