A doctor believes that the variance of systolic blood pressure is 470. A random sample of 20 patients found a variance of 525. Assume the variable is normally distributed and a - 0.05. Using the chi-square distribution, find the critical value(s) for a two-tailed test. 9.591 and 34.170 10.851 and 31.410 10.177 and 30.144 8.907 and 32,852

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 7.97.9 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 2424 samples is 8.18.1 ppm with a variance of 0.250.25. Does the data support the claim at the 0.10.1 level? Assume the population distribution is approximately normal. Step 3 of 5:  Specify if the test is one-tailed or two-tailed.

A random sample of 10 subjects have weights with a standard deviation of 13.0649 kg. What is the variance of their weights? Be sure to include the appropriate units with the result. ..... The variance of the sample data is (Round to four decimal places as needed.) MacBook DD 80 000 000 F9 F10 esc F5 F7 F8 F2 F3 F4 F6 F1 & #3 7 8 9

Assume that you have been provided the following information for a sample of cars The covariance between weight and miles per gallon is equal to -4.9 pound-miles. The standard deviation of the cars' mileages is 7.75. The standard deviation of the cars' weights is 0.94. Estimate the correlation coefficient to the first decimal place.

The average score on a statistics test was 2.52 with a standard deviation of 0.75. The teacher suspects that the exam was very difficult; Based on the above, he wants to adjust the scores so that the mean is 3.58 and the standard deviation is 0.25. Compute the values a and b such that the fit of type aX+b provide the desired mean and variance? Calculate: a=?b=?

A sample of 100 scores has a mean of 58, a variance of 160, and an estimated standard error of 4. Which of these values is guaranteed to increase if the sample size is decreased to 10? a. none of these is likely to be changed very much by decreasing n.   b. the value of the variance   c. the value of the mean   d. the value of the standard error

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 4.6 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 14 samples is 4.9 ppm with a variance of 1.2 Does the data support the claim at the 0.01 level? Assume the population distribution is approximately normal. Step 2 of 5 :   Find the value of the test statistic. Round your answer to three decimal places.

What is the value of n (the number of observations)? What is the value of Se (standard error for the model) (2 decimals)? What is the average of the x variable (2 decimals)? What is the variance of the x variable (1 decimal)?

Compute the (sample) variance and standard deviation of the data sample. (Round your answers to two decimal places.) −1, 7, 7, 3, 14 Variance: Standard Deviation: