Answer:
the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
Step-by-step explanation:
since the variance S² of the batch follows a normal distribution , then for a sample n of 20 distributions , then the random variable Z:
Z= S²*(n-1)/σ²
follows a χ² ( chi-squared) distribution with (n-1) degrees of freedom
since
S² > 3.10 , σ²= 1.75 , n= 20
thus
Z > 33.65
then from χ² distribution tables:
P(Z > 33.65) = 0.02020
therefore the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
We know by definition that complementary angles add up to 90 degrees. We can set up an equation using the ration given:
17x+13x=90, with x representing the amount you need to multiply the ratio by to get 90.
17x+13x=90
30x=90
x=3
We now know that the number we multiply the ratio by is 3. The smaller number in the ratio is 13, and so therefore we multiply it by 3.
3*13=39
The answer is 39 degrees.
Answer: 4.27% of adults in the USA have stage 2 high blood pressure.
Step-by-step explanation:
Let x be a random variable that denotes a person with high blood pressure .
Given: Average blood pressure: 
Standard deviation: 
Someone qualifies as having Stage 2 high blood pressure if their systolic blood pressure is 160 or higher.
The probability that an adult in the USA have stage 2 high blood pressure:
![P(x\geq160)=P(\dfrac{x-\mu}{\sigma}}\geq\dfrac{160-122}{22})\\\\=P(z\geq1.72)\ \ \ [z=\dfrac{x-\mu}{\sigma}]\\\\=1-P(z](https://tex.z-dn.net/?f=P%28x%5Cgeq160%29%3DP%28%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%7D%5Cgeq%5Cdfrac%7B160-122%7D%7B22%7D%29%5C%5C%5C%5C%3DP%28z%5Cgeq1.72%29%5C%20%5C%20%5C%20%5Bz%3D%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%5D%5C%5C%5C%5C%3D1-P%28z%3C1.72%29%5C%5C%5C%5C%3D1-0.9573%5C%20%5C%20%5BBy%5C%20p-value%5C%20table%5D%5C%5C%5C%5C%3D0.0427%3D4.27%5C%25)
Hence, 4.27% of adults in the USA have stage 2 high blood pressure.
The answer is 637.222 in^2
Because I am right
