1 True or False Z distributions and t distributions are simi

1) True or False: Z distributions and t distributions are similar in that they vary with degrees of freedom (df)

2) True or False: the t and z distributions look exactly the same if the sample size is at least 30

3) If you want to know whether drug A results in a greater mean blood count than 25, your alternative hypothesis will be:

a) Left Tailed

b) Right Tailed

c) 2 tailed

4) If you want to know whether the average grade in biometrics has changed from a mean of 83%, your alternative hypothesis will be

a) Left Tailed

b) Right Tailed

c) 2 tailed

5) You complete a 1 population t-test for the mean. Your alternative hypothesis was 2 tailed. Your t* value was 3.4, your tcrit values were a -2.12 and a +2.12. Your conclusion should be:

a) reject the null and conclude mean is significantly less than some value

b) reject the null and conclude mean is significantly greater than some value

c) reject the null and conclude the mean was significantly different from some value

d) do not reject the null.

Solution

1.false
2.true
3.b) Right Tailed
4.a) Left Tailed
5.b)   reject the null and conclude mean is significantly greater than some value