A psychologist is studying smokers' self-images, which she measures using the self-image (SI) score from a personality inventory. She would like to examine the mean SI score u for the population of all smokers. Previously published studies have indicated that the mean SI score for the population of all smokers is 85 and that the standard deviation is 12, but the psychologist has good reason to believe that the value for the mean has decreased. She decides to perform a statistical test and chooses a random sample of 75 smokers' SI scores. She'll use the value 12 for the population standard deviation, and she'll test at the 0.05 level of significance. Based on this information, answer the questions below. Carry your intermediate computations to four or more decimal places, and round your responses as indicated. (If necessary, consult a list of formulas.) (a) What are the null hypothesis H, and the alternative hypothesis H, that the psychologist should use for the test? Họ: 0 H1: 0 믐 D=0 Oso (b) Assuming that the actual value of u is 82, what is the probability that the psychologist commits a Type Il error? Round your response to two or more decimal places. (c) What is the probability that the psychologist commits a Type I error? Round your response to two or more decimal places.

Miranda and Karla began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Miranda took a test in Social Studies and earned a 71.4, and Karla took a test in Art History and earned a 60.9. Use the fact that all the students' test grades in the Social Studies class had a mean of 75.3 and a standard deviation of 10.7, and all the students' test grades in Art History had a mean of 66.4 and a standard deviation of 10.3 to answer the following questions.a) Calculate the z-score for Miranda's test grade.z=b) Calculate the z-score for Karla's test grade.z=c) Which person did relatively better? Miranda Karla They did equally well.

A psychologist is studying the self image of smokers, as measured by the self-image (SI) score from a personality inventory. She would like to examine the mean SI score, μ, for the population of all smokers. Previously published studies have indicated that the mean SI score for the population of all smokers is 82and that the standard deviation is 12, but the psychologist believes that the value for the mean has decreased. She plans to perform a statistical test. She takes a random sample of SI scores for smokers and computes the sample mean to be 7.Based on this information, answer the questions below. What are the null hypothesis (H0) and the alternative hypothesis (H1) that should be used for the test?H0: μ is ?less than less than or equal togreater thangreater than or equal to not equal toequal to ? 82 74 12 H1: μ is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ? 82 74 12 In the context of this test, what is a Type II error?A Type…

A psychologist is studying the self image of smokers, as measured by the self-image (SI) score from a personality inventory. She would like to examine the mean SI score,  μ , for the population of all smokers. Previously published studies have indicated that the mean SI score for the population of all smokers is  80  and that the standard deviation is  12 , but the psychologist believes that the value for the mean has decreased. She plans to perform a statistical test. She takes a random sample of SI scores for smokers and computes the sample mean to be  74 . Based on this information, answer the questions below. What are the null hypothesis ( H0 ) and the alternative hypothesis ( H1 ) that should be used for the test? H0 :  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012 H1 :  μ  is ?less thanless than or equal togreater thangreater than or equal tonot equal toequal to ?748012In the…

You are a public health researcher.  You want to see if the average age that a person starts smoking has changed over time.  Smokers are recruited to answer a survey that asked at what age they started smoking.  You divided participants into two groups, one is participants under the age of 30 and the second for participants over the age of 30.  The average age for the two groups were compared. Which statistical test would be best to determine if there is a significant different in starting age between the two groups.     one-sample t-test     related samples t-test     independent samples t-test     ANOVA

Logan and Brian began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Logan took a test in Art History and earned a 76.8, and Brian took a test in English and earned a 68.9. Use the fact that all the students' test grades in the Art History class had a mean of 71.9 and a standard deviation of 11.6, and all the students' test grades in English had a mean of 61 and a standard deviation of 9.4 to answer the following questions.a) Calculate the z-score for Logan's test grade.z=z= [Round your answer to two decimal places.] b) Calculate the z-score for Brian's test grade.z=z= [Round your answer to two decimal places.]c) Which person did relatively better? Logan Brian They did equally well.

So far, Walter has scores of 18, 17, 19, and 21 points for the first four science quizzes. What does he need to score on the next quiz in order to achieve an average(mean) score of 20 points per quiz?