Does delaying oral practice hinder learning a foreign language? Researchers randomly assigned 25beginning students of Russian to begin speaking practice immediately and another 25 to delayspeaking for four weeks. At the end of the semester both groups took a standard test ofcomprehension of spoken Russian. Suppose that in the population of all beginning students, the testscores for early speaking vary according to the N(32,6) distribution and scores for delayed speakinghave the N(29,5) distribution5.What is the sampling distribution of the mean score in the early-speaking group in manyrepetitions of the experiment? What is the sampling distribution of the mean score y in thedelayed-speaking group?а.b.Are the sampling distributions approximately Normal or exactly Normal? Why?If the experiment were repeated many times, what would be the sampling distribution of thedifference y - 3 between the mean scores in the groups?c.d.What is the probability that the experiment will find (misleading) that the mean score for delayedspeaking is at least as large as that for early speaking?

a. The sampling distribution of the mean score of x in the early speaking group in many repetitions…

Answered: Does delaying oral practice hinder…

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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A random sample of n1 = 157 people ages 16 to 19 were taken from the island of Oahu, Hawaii, and 12 were found to be high school dropouts. Another random sample of n2 = 129 people ages 16 to 19 were taken from Sweetwater County, Wyoming, and 6 were found to be high school dropouts. Do these data indicate that the population proportion of high school dropouts on Oahu is different (either way) from that of Sweetwater County? Use a 1% level of significance. (a) What is the level of significance? What is the value of the sample test statistic? (Test the difference p1 − p2. Do not use rounded values. Round your final answer to two decimal places.) (c) Find (or estimate) the P-value. (Round your answer to four decimal places.)
Does grade level matter regarding having a drink of coffee before going to school? To get some insight relating to this question, Professor Jay randomly selected nm = 1142 New York City high school freshmen. Of these, xm = 803 said they had at least one cup of coffee before going to school. Professor Jay also randomly selected nf = 1012 New York City high school seniors. Of these, xf = 760 said they had at least one cup of coffee before going to school. Suppose Pm is the true proportion of New York City high school freshmen who have a drink of coffee before going to school. Suppose pf is the true proportion of New York City high school seniors who have a drink of coffee before going to school. Pm and pf are unknown and we will examine relations between them based upon Professor Jay's samples. Let pmhat be the sample proportion of high school freshmen who said they had at least one cup of coffee before going to school. Let pfhat be the sample proportion of high school seniors who said…
A fitness course claims that it can improve an individual's physical ability. To test the effect of a physical fitness course on one's physical ability, the number of sit-ups that a person could do in one minute, both before and after the course, was recorded. Ten individuals are randomly selected to participate in the course. The results are displayed in the following table. Can it be concluded, from the data, that participation in the physical fitness course resulted in significant improvement? Let d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course)d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course). Use a significance level of α=0.05 for the test. Assume that the numbers of sit-ups are normally distributed for the population both before and after taking the fitness course. Sit-ups before 42 42 23 32 30 42 25 47 35 38 Sit-ups after…
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