Concept explainers
Correcting for a Finite Population In a study of babies born with very low birth weights, 275 children were given IQ tests at age 8. and their scores approximated a
a. When considering the distribution of the
b. Find the
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Chapter 6 Solutions
Elementary Statistics (13th Edition)
- The mean and standard deviation of hemoglobin level of 23 vibrant students and 21 school children were found to be 10g/dl,2.2g/dl and 14g/dl, 2.2g/dl respectively.is there statistically significant difference with the average hemoglobin of the two groups?arrow_forwardthe mean and standard deviation of hemoglobin level of 23 vagrant students and 21 school children were found to be 10 g/dl, 2.2g/dl and 14g/dl, 2.9g/dl respectively. Is there statistically significant difference with the average hemoglobin of the two groups?arrow_forwardPls provide p value too. thank youarrow_forward
- The price paid for a new phone of a particular model follows a Normal distribution with mean μ=750 and standard deviation σ= 42. What proportion of these phones are purchased for more than 821 dollars? Give your answer to four decimal places. A study of 25 online jewelry retailers was done to find the statistical relationship between the price yyin dollars of a diamond ring and the weight xxin carats of the diamond. Based on this data the following least-squares regression line was found: y^=−6047.75+11975.14x What is the predicted price of diamond ring a 2.2 carat diamond using this regression line. Round your answer to two decimal places. A study of 25 online jewelry retailers was done to find the statistical relationship between the price yy in dollars of a diamond ring and the weight xx in carats of the diamond. Based on this data the following least-squares regression line was found: y^=−6047.75+11975.14x One online retailer sells a 3.00 carat diamond ring for 28,999…arrow_forwardThe average duration of labor from the first contraction to the birth of the baby in women over 35 who have not previously given birth and who did not use any pharmaceuticals is 16 hours. Suppose you have a sample of 35 women who exercise daily, and who have an average duration of labor of 16.9 hours and a sample variance of 39.7 hours. You want to test the hypothesis that women who exercise daily have a different duration of labor than all women. Calculate the t statistic. To do this, you first need to calculate the estimated standard error. The estimated standard error is SM = The t statistic is Now suppose you have a larger sample size n = 89. Calculate the estimated standard error and thet statistic for this sample with the same sample average and the same standard deviation as above, but with the larger sample size. The new estimated standard error is The new t statistic is Note that the t statistic becomes as n becomes larger. Use the Distributions tool to look at thet…arrow_forwardIs should be reject or not?arrow_forward
- Find the least value of r in a sample of 18 pairs of observations from a bi-variate normal population significant at 5% significance level.arrow_forwardint onodqolot o gnnu noiesup examine profit as a percentage of stockholder equity. A random sample of 31 retail stocks such as How profitable are different sectors of the stock market? One way to answer such a question is to Toys 'R' Us, Best Buy, and Gap was studied for x1, profit as a percentage of stockholder equity. The result was sample mean of 14.7. A random sample of 36 utility (gas and electric) stocks such 133 80 113 .s Boston Edison, Wisconsin Energy, and Texas Utilities was studied for x2, profit as a nercentage of stockholder equity. The result was a sample mean of 9.8. Assume that gi = 3.4 and 02 = 3.8. N, = 31 >X,=TH:1,0,=3.4, n2= 36, E,=9.8,0a C.L:0.95 At the 95% level of confidence, does it appear that the profit as a percentage of stockholder equity for retail stocks is higher than that for utility stocks? (Show your confidence in interval notation and show your interpretation) 2 Sampz %3D 3.1751 < M,- Azs 6.6243 We are 95% level Conzidence that the Profit Jol letail…arrow_forwardAlthough, there is a population belief that herbal remedies such as ginko biloba and ginseng may improve learning and memory in healthy adults, these effects are usually not supported by well controlled research. In a typical study a researcher obtains a sample of n=16 participants and has each person take the herbal supplements every day for 90 days., Each person takes a standardized memory test. For the general population scores from the test form a normal distribution with mean of u= 50 and standard deviation sigma =12. The sample of research participants had an average of M = 54. a) Assuming a two tailed test state the null hypothesis in a sentence that includes the two variables being examined. b) Using the standard 4-step procedure, conduct a two tailed test with (x = 0.05 to evaluate the effect of the supplement.arrow_forward
- The average duration of labor from the first contraction to the birth of the baby in women over 35 who have not previously given birth and who did not use any pharmaceuticals is 16 hours. Suppose you have a sample of 33 women who exercise daily, and who have an average duration of labor of 16.9 hours and a sample variance of 20.3 hours. You want to test the hypothesis that women who exercise daily have a different duration of labor than all women. Calculate the t statistic. To do this, you first need to calculate the estimated standard error. The estimated standard error is sMM= . The t statistic is . Now suppose you have a larger sample size n = 81. Calculate the estimated standard error and the t statistic for this sample with the same sample average and the same standard deviation as above, but with the larger sample size. The new estimated standard error is . The new t statistic is . Note that the t statistic becomes as n becomes larger. Use…arrow_forwardYou are interested in exploring the relationship between serum homocysteine levels and endometriosis. You collect data from 100 randomly selected people with endometriosis. Your sample has a mean serum homocysteine level of 47 µmol/L. You know that the mean homocysteine for healthy people who can develop endometriosis (ie. Have an endometrium) is 25 µmol/L with a standard deviation of 15 µmol/L. Use hypothesis testing to determine whether your sample (mean 47 µmol/L) has different levels of homocysteine than healthy people who can develop endometriosis (ie. We want to know whether those with endometriosis have different levels of homocysteine than the population of people who can develop endometriosis but are healthy) Identify a null and alternative hypothesis for a two-sided test. Calculate a z score for this data and depict the z score on a standard normal curve. You are welcome to draw the distribution on your computer or draw it by hand. Include the image in your…arrow_forwardChoose the correct answer and show a hand written solutionarrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill