Question about Statistics - Multiple Choice Questions

1) If Larry gets a 70 on a physics test where the mean is 65 and the standard deviation is 5.8, where does he stand in relation to his classmates? (Points: 5)
He is in the top 10%.
He is in the top 20%.
He is in the bottom 20%.
He is in the bottom 10%.

2. Let's assume you have taken 100 samples of size 64 each from a normally distributed population. Calculate the standard deviation of the sample means if the population's variance is 49. (Points: 5)
0.875
0.125
0.766
0.587

3. Find P(11 < x < 16) when mu = 15 and sigma = 3. (Points: 5)
0.6293
0.3707
0.0918
0.5375

4. Interpret a 90% confidence interval of (4.355, 4.445) for a population mean.

5. ) In the standard normal distribution, the variance is always (Points: 5)
0
1
2
none of these

6. The area under a normal curve with mu = 15 and sigma = 2 is (Points: 5)
0
1
2
none of these