
So, the first thing you probably did was note that there was 1% here and 1%

here, so that the total area under the normal curve adds to 100%. So now, let's

bring up the Z table. So, we're looking for a proportion of 0.01, that's under

the curve to the left of the Z score. Our closest bet is right here, 0.0099. So

that's the closest value in the Z table to 0.01, or 1%. And that corresponds to

a Z squared of negative 2.33. So this Z squared value is going to be negative

2.33, and you should have written here positive 2.33. So, 98% of sample means

fall within positive 2.33 standard errors from the population mean.