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:
1 . Closure
2. Distributive
3. Closure
Step-by-step explanation:
Here, we want to know the type of property exhibited or displayed by each of the equations in the question.
Equation 1 displays the closure property.
What this means that if we make an addition operation either way, we would get same answer. So we say that addition is closed for that equation.
Equation 3 exhibits closure property as well. If we go either way on the addition operation for that equation, we are bound to get the same answer.
Equation 2 exhibits the distributive property.
Each term in the bracket is multiplied by the subtraction symbol before we proceeded to complete the arithmetic operations
7x-8 (2) = 12x+8
14x-16 = 12x+8
-12x -12x
2x-16 = 8
+16 +16
2x = 24
÷2 ÷2
x= 12
UV= 7x-8
UV= 7(12)-8
UV= 84-8
UV= 76
We can use the sum of an aritmetic sequence
the sum from n=1 to n=r when the first term is a1 and the nth term is an is

first term is 1
last term is 100
there are 100 terms so n=100
so the sum is


S=5050
now you want us to divide by 10
5050/10=505
fun fact, gauss (famous math guy) did this when he was younger, legend has it that he was assigned this as an in class assigment to kill time but gauss found a neat pattern, he noticed that adding the end terms wer giving the same sum, example, 100+1=101, 2+99=101, etc, so he just needed to find al the pairs and add them all up
answer is 505
the result is 505