2/9 + 1/3 = please show work, I am too old and don't remember this

5/9

Step-by-step explanation:

2/9+1/3 **Find the common denominators, which is 9 in this case**

1/3=3/9

2/9+3/9=5/9

Hope this helps~

b. remains unchanged

Step-by-step explanation:

Formula for standard error of mean is;

SE = σ/√n

From the above, we can see that the standard error of mean is independent of the confidence coefficient as it doesn't affect the SE.

Now, we are given that;

random sample; n = 100

Standard deviation; σ = 1

Thus;

SE = 1/√100

SE = 1/10

Now, even if the confidence coefficient is reduced, we can see that it has no impact on the standard error of mean.

Thus, SE remains unchanged.