I'm sorry, I cannot fully transcribe the content from the image as it's partially cut off and unclear. However, here's an attempt to summarize the visible content:The text discusses a study by Montarello and Martens (2005), which found that fifth-grade students completed more mathematics problems accurately when simple problems were included alongside regular assignments. To investigate this phenomenon further, a researcher might use a standardized math achievement test, assumes scores follow a normal distribution with a mean (μ) of 100 and a standard deviation (σ) of 18. The researcher modifies the test by adding easy questions, gives it to a sample of 36 students, resulting in a mean score (M) of 104. The inquiry is whether these modifications notably improve student performance, using a one-tailed test with α = .01.If you would like further assistance, please feel free to ask!

Null Hypothesis: A hypothesis which is tested for plausible rejection is called the Null Hypothesis…

Answered: Montarello and Martens (2005) found…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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(b) The team at the Natural-Life company goes out to the city to sell daily. John is a member of the team. He claims that on average, he sells $50,000 worth of their product to each store that he visits per week. The new manager is wary of this claim and believes he may be overstating his sales. To test the claim, the manager took a random sample of 27 stores that the sales representative usually visits weekly and found that the mean amount earned was $48,950 with a standard deviation of $1,250. At the 0.01 level of significance, can it be concluded that John is overestimated his sales? … (ie. his sales might be less than he claimed)
If x̄=89, σ=13, and n=70, construct a 95% confidence interval estimate of the population mean, μ. ____≤μ≤______ (Round to two decimal places as needed.)
Consider the trash bag problem. Suppose that an independent laboratory has tested trash bags and has found that no 30-gallon bags that are currently on the market have a mean breaking strength of 50 pounds or more. On the basis of these results, the producer of the new, improved trash bag feels sure that its 30-gallon bag will be the strongest such bag on the market if the new trash bag's mean breaking strength can be shown to be at least 50 pounds. The mean of the sample of 39 trash bag breaking strengths in Table 1.10 is x = 50.573. If we let u denote the mean of the breaking strengths of all possible trash bags of the new type and assume that o equals 1.61: Using the 95 percent confidence interval, can we be 95 percent confident that u is at least 50 pounds?
Three experiments investigating the relation between need for cognitive closure and persuasion were performed. Part of the study involved administering a "need for closure scale" to a group of students enrolled in an introductory psychology course. The "need for closure scale" has scores ranging from 101 to 201. For the 71 students in the highest quartile of the distribution, the mean score was x = 177.10. Assume a population standard deviation of ? = 7.51. These students were all classified as high on their need for closure. Assume that the 71 students represent a random sample of all students who are classified as high on their need for closure. How large a sample is needed if we wish to be 99% confident that the sample mean score is within 2.2 points of the population mean score for students who are high on the need for closure?
QUESTION 2 In 2003, Major League Baseball took steps to speed up the paly of baseball games and make games a more consistent duration. In a sample of 41 games in 2002, the average duration of a game was 2 hours and 58 minutes with a standard deviation of 30 minutes. A similar survey in 2003 of 31 games found that the average duration was 2 hours and 40 minutes with a standard deviation of 22 minutes. When testing the hypothesis (at the 10% level of significance) that the variance has been reduced, what is the critical value? (please round your answer to 2 decimal places)
Last week Jenni had exams in Spanish and in Cognition. She scored 5 points above the mean on both exams. From this information, what can you conclude about the z-scores for Jenni’s two scores? a. Jenni will have a higher z-score for the exam with the lower mean. b. None of the other choices is correct. c. Jenni has identical z-scores for the two exams. d. Both of Jenni's z-scores are positive.
Three experiments investigating the relation between need for cognitive closure and persuasion were performed. Part of the study involved administering a "need for closure scale" to a group of students enrolled in an introductory psychology course. The "need for closure scale" has scores ranging from 101 to 201. For the 65 students in the highest quartile of the distribution, the mean score was x = 175.10. Assume a population standard deviation of ? = 7.55. These students were all classified as high on their need for closure. Assume that the 65 students represent a random sample of all students who are classified as high on their need for closure. How large a sample is needed if we wish to be 99% confident that the sample mean score is within 1.5 points of the population mean score for students who are high on the need for closure? (Round your answer up to the nearest whole number.)students
A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36 adults. The subjects complete a series of working memory tests before and after walking in an urban setting. Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher. The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the null and alternative hypotheses as: H00 : μDD = 0 H11 : μDD ≠ 0 Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statistics for his hypothesis test: Mean difference (MDD) 1.4 Estimated population standard deviation of the differences (s) 1.6 Estimated standard error of the mean differences (sMDMD) 0.2667 Degrees of freedom (df) 35 The t statistic 5.25 The critical values of t…
In general, men have greater income than women. So, a researcher hypothesizes that men’s occupational prestige scores on average should be significantly higher than women’s. The following table shows the OPS by gender. The researcher wants to test the hypothesis at the .05 level. The estimated standard error of the difference between means is 1.0. Is it going to be a one-tailed test, or a two-tailed test? A. One-tailed test B. Two-tailed test
A psychologist finds that fidgety patients tap their fingers on average 500 times during a 2 hour period. You wish to test this claim for the same patients, but in a room decorated with soothing colors and soft lighting. You believe that a warmly decorated room may alter the fidgeting behavior, causing subjects to tap their fingers less than they do under normal conditions. A random sample of 400 patients has a mean of 420 taps and a standard error of 30 taps in a 2 hour period. Find the margin of error for the average tapping of fingers during a 2 hour period.
Three experiments investigating the relation between need for cognitive closure and persuasion were performed. Part of the study involved administering a "need for closure scale" to a group of students enrolled in an introductory psychology course. The "need for closure scale" has scores ranging from 101 to 201. For the 75 students in the highest quartile of the distribution, the mean score was x = 176.90. Assume a population standard deviation of ? = 7.71. These students were all classified as high on their need for closure. Assume that the 75 students represent a random sample of all students who are classified as high on their need for closure. Find a 95% confidence interval for the population mean score ? on the "need for closure scale" for all students with a high need for closure. (Round your answers to two decimal places.)
3. ACT scores are roughly Normal with mean 20.8 and standard deviation 4.8, and SAT scores are roughly Normal with mean 1026 and standard deviation 209. Some students take both. For those students, the correlation between the two scores is 0.72. a. What's the equation of the straight line that you'd use to predict ACT scores based on SAT scores? b. I got a 1300 on the SAT, and I'm planning to take the ACT. Predict what I might get, c. What's the equation of the straight line that you'd use to predict SAT scores based on ACT scores? d. My friend got a 27 on the ACT, and she's planning to take the SAT. Predict what she might get. e. How come you're predicting both that I'll do worse than her on the ACT and that she will do worse than me on the SAT? 4. Draw a simple random nlc of size 15 from the labels 40os01, 402.

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