A random sample of 83 eighth grade students' scores on a national mathematics assessment test has a mean score of 275. This test result prompts a state school administrator to declare that the mean score for the state's eighth graders on this exam is more than 270. Assume that the population standard deviation is 30. At a = 0.02, is there enough evidence to support the administrator's claim? Complete parts (a) through (e). (a) Write the claim mathematically and identify Ho and H,. Choose the correct answer below. O A. Ho: u= 270 (claim) H u> 270 O B. Ho: uz 270 (claim) H, u<270 OC. Ho u<270 Ha u2270 (claim) O D. Ho: = 270 H u> 270 (claim) O E. Ho us270 (claim) O F. H, us270 H u> 270 (claim) H, u> 270

The time taken for a computer to boot up, X, follows a mound-shaped (i.e. bell-shaped) distribution with a mean of 30 seconds and a standard deviation of 5 seconds. What is the standardized score for a boot up time of... a. x = 30 seconds? b. x = 20 seconds? c. x = 35 seconds? 1 Z-Score = Z-Score = Z-Score = h

According to the College Board, scores on the math section of the SAT Reasoning college entrance test for the class of 2010 had a mean of 516 and a standard deviation of 116. Assume that they are roughly normal.One of the quartiles of the scores from the math section of the SAT Reasoning test is 438. The other quartile is _______.

Apply Chebyshev's rule to answer the following question. A quantitative data set has mean 20 and standard deviation 2. At least what percentage of the observations lie between 14 and 26? At least % of the observations lie between 14 and 26. KRound to the nearest integer as needed.)

As Director of Admissions at Garden Valley University, you believe that the average age of full-time students (Group 1) is less than the average age of part-time students (Group 2). You sample 45 full-time students, and the sample mean age is 22.3 with a standard deviation of 4.8. You sample 50 part-time students, and the sample mean age is 24.3 with a standard deviation of 5.6. Test the claim using a 2% level of significance. Assume the population standard deviations are unequal and that both populations are normally distributed. Where necessary, round results accurate to 4 decimal places. a. What are the correct hypotheses? Null: Ο Ho: μ = 0 O Ho: ₁ = ₂ Ho: M₁ M₂ Ο Ho: μ = 22.3 Alternative: Ο HA: Mı # με Ο HA: μ. > με HA: ₁2 HA: < 0 Ο HA: μ + 22.3 b. What is the correct distribution to use for the test? Select an answer c. What is the test statistic? d. What is the p-value? p-value = e. The correct decision is to Select an answer f. INTERPRET the conclusion in the context of the…

A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $52. Complete parts (a) and (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $51? (Use a 0.01 level of significance.) State the null and alternative hypotheses. Ho: H (Type integers or decimals. Do not round. Do not include the $ symbol in your answer.) Identify the critical value(s). The critical value(s) is/are (Type an integer or a decimal. Round to two decimal places as needed. Use a comma to separate answers as needed.) Determine the test statistic. The test statistic, 1STAT, is (Type an integer or a decimal. Round to two decimal places as needed.) State the conclusion. Ho. There is evidence that the…

The standard deviation of the population of IQ Scores is standardized to be 15 points. Calculate the standard error of the mean(nearest hundredth place) for:   A sample of size of 81   A sample size of 4

A marketing researcher wants to estimate the mean amount spent per year​ ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of ​$58and a standard deviation of ​$55.Complete parts​ (a) and​ (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from ​$51​? ​(Use a 0.01 level of​ significance.)   State the null and alternative hypotheses.

Are you smarter than a second-grader? A random sample of 59 second-graders in a certain school district are given a standardized mathematics skills test. The sample mean score is X=56. Assume the standard deviation of test scores is o= 15. The nationwide average score on this test is 50. The school superintendent wants to know whether the second-graders in her school district have greater math skills than the nationwide average. Use the a = 0.05 level of significance and the P-value method with the TI-84 calculator. Answer the following questions.

A random sample of five observations from three normally distributed populations produced the following data: (You may find it useful to reference the F table.) (table is the screenshot picture) a. Calculate the grand mean. (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.) b. Calculate SSTR and MSTR. (Round intermediate calculations to at least 4 decimal places and final answers to 4 decimal places.) c. Calculate SSE and MSE. (Round intermediate calculations to at least 4 decimal places and final answers to 4 decimal places.) d. Specify the competing hypotheses in order to determine whether some differences exist between the population means. _H0: μA = μB = μC; HA: Not all population means are equal. _H0: μA ≤ μB ≤ μC; HA: Not all population means are equal. _H0: μA ≥ μB ≥ μC; HA: Not all population means are equal.   e-1. Calculate the value of the F(df1, df2) test statistic. (Round intermediate calculations to at least 4 decimal…