Answer:
t = -1.428
Step-by-step explanation:
Average blood pressure among people with high responsibility jobs = u = 140 mm
Number of people sampled for the study = n = 51
Average blood pressure of the sample = x = 139 mm
Standard deviation of the sample = s = 5 mm
The claim is that practicing yoga decreases the blood pressure. So we have to test that after practicing yoga, the average blood pressure will be lesser than 140. Based on this we can formulate the null and alternate hypothesis as:
Null Hypothesis: 
Alternate Hypothesis: 
Since population standard deviation is not known, we cannot use z-distribution for this test. We are given the value of sample standard deviation, so t-test will be used for this case.
Test statistic is calculated as:

Using the values in this formula gives us:

Therefore, the value of test statistic is -1.428
Answer:
Approximately Normal
Step-by-step explanation:
Since the population is normally distributed, the sampling distribution of the sample mean will also be normally distributed, even when the sample size is small.
Okay well the starting is 28 dollars, right. But since there is a 20 percent discount, you have to turn 20% to a decimal. That means moving the decimal sign twice to the left to make it .20. From the it would be .20*28, that should equal 5.6. Now, that 5.6 is the amount you have to take away, it is the price of the sale. From then, you subtract which is 28-5.6 which should be 22.4. From that 22.4 you now take away two dollars and then it should be 22.4-2 which should be 20.4. Now that is your answer, 20.4.