statistic

1. Watch the following videos and take notes.

Null and Alternative HYpothesis

Play Video https://www.youtube.com/watch?v=702c5GA7HZ4&feature=emb_title

Z Statistic vs. T-statistic

Play Video  https://www.youtube.com/watch?v=5ABpqVSx33I&feature=emb_title

T statistic confidence interval

Play Video  https://www.youtube.com/watch?v=hV4pdjHCKuA&feature=emb_title

Answer the following questions

2. Summarize the key points about the null and alternative hypothesis (7)

3. You are the manager of a fast food restaurant.  You want to determine whether the waiting to place an order has changed in the last month from its previous population mean value of 4.5 minutes.  From past experience, you can assume that the population standard deviation is 1.2 minutes.  You select a sample of 25 orders during a one-hour period. The sample mean is 5.1 minutes.  USE THE 6-STEP APPROACH in chapter 9 to determine whether there is evidence at the .05 level of significance that the mean waiting time is place an order has changed in the last month from its previous mean value of 4.5 minutes.  (You must do all 6 steps to receive credit for this problem)

1. The null hypothesis is 

2. 

3. 

4.

5. 

6. 

3. What is it meant by the power of a test?

4. What does a Z Score measure?

 5. When do you use the t distribution to develop the confidence interval estimate for the mean?

PART 2

1-What does the alpha or (α) in statistics mean, and how to get the alpha or α value?
2-When should we use the t distribution to develop the confidence interval estimate for the mean?

PART 3 +pics

why implement same “TWO TAIL TEST” (the purple shade), but we got different formula: “T.INV.(E5,E18) and T.INV.2T(E5/E18) (blue1,2)?