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:

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