19. Assume that the sample means of samples of size 10 are normally distributed. a. What...
5. Marine scientists have determined that the weights of green sea urchins are apploximately normally distributed with mean 52 grams and standard deviation ơ 15 grarns. (a) Find the probability that a randomly selected green sea urchin weighs more than 45 (b) Find the probability that a randomly selected green sea urchin weighs between 50 and grams 60 grams (c) 10% of green sea urchins weigh more than how many grams?
Random samples of size 55 are taken from a normally distributed population that has 425 elements, a population mean of 20, and a population standard deviation of 7. What is the standard deviation of the sampling distribution of the sample means?
Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 43.5 and a standard deviation of 4.1 while the second sample has a mean of 40.1 and a standard deviation of 3.2. A researcher would like to test if there is a difference between the population means at the 0.05 significance level. What can the researcher conclude? There is not sufficient evidence to reject...
4. (10 points) The Graduate Record Examination (GRE) test scores x are normally distributed this year. The mean test score is 200 and the standard deviation is 10. Random test scores samples of size 30 are drawn. (a.) Calculate the mean and standard deviation of sampling distribution of sample means. Show all work. o mean = standard deviation = isiq Sabit to o lodowa (b.) Find the probability that the mean of a sample is less that 180. Show all...
Product filling weights are normally distributed with a mean of 365 grams and a standard deviation of 19 grams. a. Compute the chart upper control limit and lower control limit for this process if samples of size 10, 20 and 30 are used (to 2 decimals). Use Table 19.3. For samples of size 10 UCL =| LCL For a sample size of 20 UCL = LCL For a sample size of 30 UCL = LCL = b. What happens to...
If the standard deviation of a normally distributed population is 60 and we take a sample of size 25, then what is the (standard error) standard deviation of the sampling distribution of sample means. * Your answer If the mean of a population is 3 points 250 and we take a sample of size 25, then what is the mean of the sampling distribution of sample means. * Your answer 3 points A certain car model has a mean gas...
A random sample of size n = 25 is obtained from a normally distributed population with population mean μ =200 and variance σ^2 = 100. a) What are the mean and standard deviation of the sampling distribution for the sample means? b) What is the probability that the sample mean is greater than 203? c) What is the value of the sample variance such that 5% of the sample variances would be less than this value? d) What is the...
A population is normally distributed with a mean of 100 and a standard deviation of 10, for samples of size 25, what is the probability of randomly sampling and getting a sample mean of 103 or more?
A normally distributed population has a mean of 76 and a standard deviation of 19. Determine the probability that a random sample of size 22 has an average between 72 and 76. Round to four decimal places.
Page 1 Question 1 Suppose we take repeated random samples of size 20 from a population with a Select all that apply. mean of 60 and a standard deviation of 8. Which of the following statements is 10 points true about the sampling distribution of the sample mean (x)? Check all that apply. A. The distribution is normal regardless of the shape of the population distribution, because the sample size is large enough. B. The distribution will be normal as...