Answer is
b. False
If I add 1.96 times the standard error of the mean, I would obtain 95% of my sample
To get 99.7% of my sample I need to add 2.58 times the standard error of the mean
Question 5 In a normal distribution, if l take the mean value and I add or...
In a normal distribution, if I take the mean value and I add or subtract 1.96 times the standard error of the mean (SEM), I would obtain 99.7% of my sample O a. True o b. False O C. We don't have enough information O d. None of the above
10. Assume that 20 people take a math test, which is not enough for a normal distribution to form. If Conrad scores three standard deviations above the mean, what percentile is he? 1. 75.0% 2. 88.5% 3. 95.0% 4. 99.7% 5. Not enough information to determine. ________________________________________ 11. Assume that 20 people take a math test, which is not enough for a normal distribution to form. If Sarah scores at the median, what percentile is she? 1. 34% 2. 50%...
2. Suppose we have a Normal distribution with mean 35 and standard deviation 4. Take a few a. minutes to draw this curve very neatly and accurately. Reference the document "How to Draw a Normal Curve" in this assessment. Use a separate sheet of paper, or add extra space here, and use a straightedge to draw an axis. b. Label your curve from part a with the 68-95-99.7 Rule. c. If we randomly select a value from this Normal model...
The time required for Dr. B's students to complete the Statistics Exam is approximately normally distributed with a mean of 40.4 minutes and a standard deviation of 2.2 minutes. Let X be the random variable "the time required for Dr. B's students to complete the Statistics Exam." 6. With the above setting what time marks the 90th percentile? A. 37.562 minutes B. 37.584 minutes C. 43.238 minutes D. 43.216 minutes E. None of the above 7. Which of the following...
1. Select all true statements about sample mean and sample median. A) When the population distribution is skewed, sample mean is biased but sample median is an unbiased estimator of population mean. B) When the population distribution is symmetric, both mean and sample median are unbiased estimators of population mean. C) Sampling distribution of sample mean has a smaller standard error than sample median when population distribution is normal. D) Both mean and median are unbiased estimators of population mean...
Question 183 pts In a normal distribution, what percentage of sample observations fall between the mean and .71 standard deviations above or below the mean? 1.96% 76.11% 26.11% 13.6%
Question 1 (0.5 points) A random variable X follows a normal distribution with mean of 50 and standard deviation of 5. Suppose we take a simple random sample of size 6 from the population above. Can we calculate the probability that the sample mean is between 45 and 60? (You do not need to actually calculate the probability for this question.) Yes, and the calculated probability would be exact. Yes, and the calculated probability would be approximate. No. Question 2...
R problem 1: The reason that the t distribution is important is that the sampling distribution of the standardized sample mean is different depending on whether we use the true population standard deviation or one estimated from sample data. This problem addresses this issue. 1. Generate 10,000 samples of size n- 4 from a normal distribution with mean 100 and standard deviation σ = 12, Find the 10,000 sample means and find the 10,000 sample standard deviations. What are the...
Question 2 (0.5 points) A random variable X follows a normal distribution with mean of 50 and standard deviation of 5. Suppose we take a simple random sample of size 60 from the population above. Can we calculate the probability that the sample mean is between 45 and 60? (You do not need to actually calculate the probability for this question.) Yes, and the calculated probability would be exact. Yes, and the calculated probability would be approximate. No. Question 3...
Suppose that we take a sample of 25 observations from a Normal distribution with a mean of 10 and a standard deviation of 4. Write 'X-bar' for the average of the sample. What is the probability that X-bar is less than 12? 0.9938 0.6915 0.3085 0.9772 0.0062