- 23 - Section 6.2 Inference for a Mean 1/1 Math Fill in the Question 17 of 21 - /1 Question 4 1/1 View Policies Math Fill in the Blank Correct Current Attempt in Progress The Autistic Brain Question 5 1/1 Math Fill in the Correct Autistic children often have a small head circumference at birth, followed by a sudden and excessive increase in head circumference Blank during the first year of life. A recent study examined the brain tissue in autopsies of seven autistic male children between the ages of 2 and 16. The mean number of neurons in the prefrontal cortex in non-autistic male children of the same age is about 1.15 billion. Question 6 The prefrontal cortex is the part of the brain most disrupted in autism, as it deals with language and social communication. In the 1/1 Math Fill in the sample of seven autistic children, the mean number of neurons in the prefrontal cortex was 1.94 billion with a standard deviation of Blank Correct 0.50 billion. The values in the sample are not heavily skewed. Use the t-distribution to test whether this sample provides evidence that autisticmale children have more neurons (on average) in the prefrontal cortex than non-autistic children. (This study indicates that the causes of autism may be present before birth.) Question 7 1/1 Math Fill in the Blank Correct Adapted from Courchesne, E., et.al., "Neuron Number and Size in Prefrontal Cortex of Children with Autism," Journal of the American Medical Association, November 2011; 306(18): 2001-2010. Question 8 1/1 Math Fill in the Blank Correct State the null and alternative hypotheses. Question 9 1/ 1 Math Fill in the Blank Correct :: # :: - 11 5 Question 2 1/1 View Policies Math Fill in the Blank Correct Current Attempt in Progress Question 3 Getting Enough Sleep? 1/1 Math Fill in the Blank Correct It is generally recommended that adults sleep at least 8 hours each night. One of the authors recently asked some of her students (undergraduate and graduate students at Harvard) how many hours each had slept the previous night, curious as to whether her students are getting enough sleep. The data are displayed in Figure 1. The 12 students sampled averaged 6.2 hours of sleep with a Question 4 1/1 standard deviation of 1.70 hours. Assuming this sample is representative of all her students, and assuming students need at least 8 Math Fill in the Correct hours of sleep a night, does this provide evidence that, on average, her students are not getting enough sleep? Blank Question 5 1/1 Math Fill in the Blank Correct Question 6 1/1 Math Fill in the Blank Correct 6 7 8 9 10 Question 7 1/1 Hours of Sleep Math Fill in the Blank Correct Figure 1 Hours of sleep for Harvard statistics students Question 8 1/1 Math Fill in the Blank Correct State the null and alternative hypotheses. Question 9 1/1 Math Fill in the Question 9 1 rarrart 1 1 Math Fill in the :: = :: # :: : p :: p :: 8 :: p Correct : p1 :: x1 Blank :: P :: P1 : P2 Question 10 1/1 Math Fill in the Blank Correct Ho: VS Ha: Question 11 1/1 Math Fill in the Correct Blank e Textbook and Media Question 12 1/1 Math Fill in the Correct Blank Question 13 Give the test statistic and the p-value and state the conclusion of the test. 1/1 Math Fill in the Blank Correct Round your answer for the test statistic to two decimal places and your answer for the p-value to three decimal places. test statistic = Question 14 1/1 Math Fill in the Blank Correct p-value = i Question 15 1/1 Conclusion: Ho. Multipart Correct e Textbook and Media Question 16 1/1 Multipart Correct Question 17 Multipart Not started Does the sample provide evidence that, on average, her students are not getting enough sleep? Question 18 Multipart Not started O Yes O No Question 19 -/1 Multipart Not started eTextbook and Media Viewing -/ 1 Question 20 Not started Multipart Save for Later Attempts: 0 of 4 used Submit Answer Question 21- 23 - Section 6.2 Inference for a Mean Question 21 of 21 - 11 3 Question List X View Policies Current Attempt in Progress Question 1 1/1 Math Fill in the Blank Correct Homes for Sale Question 2 1/1 The dataset HomesForSale has data on houses available for sale in three Mid-Atlantic states (NY, NJ, and PA). Table 1 shows the Math Fill in the Blank Correct mean and standard deviation from the three Mid-Atlantic states, in thousands of dollars. Use this table, the knowledge that within the US the average house sells for about 265 thousand dollars, and a 5 % significance level to answer the following questions. Question 3 1/1 Std. Math Fill in the Blank Correct State Mean Dev. New York 30 565.6 697.6 Question 4 1/1 Math Fill in the Blank Correct New Jersey 30 388.5 224.7 Pennsylvania 30 249.6 179.3 Question 5 1/1 Math Fill in the Blank Correct Table 1 Mean housing prices for New York, New Jersey, and Pennsylvania Question 6 1/1 Math Fill in the Blank Correct Click here for the dataset associated with this question. Question 7 1/1 Math Fill in the Blank Correct 1 According to the US Census in April 2011. Question 8 1/1 Math Fill in the Blank Correct (a) Test whether the average cost of a house in New York is significantly greater than the US average. Give the test statistic and the p-value. Question 9 1/1 Math Fill in the Blank Correct Round your answer for the test statistic to two decimal places and your answer for the p-value to three decimal places. test statistic = i Question 10 1/1 Math Fill in the Blank Correct p-value = i Question 11 1/1 Math Fill in the Blank Correct Is the average cost of a house in New York significantly greater than the US average? Question 12 1/1 Math Fill in the Blank Correct e Textbook and Media Question 13 1/1 Math Fill in the Blank Correct Question 14 1/1 (b) Test whether the average cost of a house in New Jersey is significantly greater than the US average. Math Fill in the Blank Correct Give the test statistic and the p-value. Question 15 1/1 Multipart Correct Round your answer for the test statistic to two decimal places and your answer for the p-value to three decimal places. test statistic = i Question 16 1/1 Multipart Correct p-value = i Question 17 - /1 Multipart Not started Is the average cost of a house in New Jersey significantly greater than the US average? Question 18 /1 Multipart Not started e Textbook and Media Question 19 - /1 Multipart Not started Question 20 - /1 (c) Test whether the average cost of a house in Pennsylvania is significantly greater than the US average. Multipart Not started Give the test statistic and the p-value. Viewing - /1 Round your answer for the test statistic to two decimal places and your answer for the p-value to three decimal places. Question 21 Not started Multipart test statistic = i p-value = i Is the average cost of a house in Pennsylvania significantly greater than the US average? e Textbook and Media (d) Which state shows the most evidence that the state average is greater than the US average? O New York O New Jersey Pennsylvania e Textbook and Media Save for Later Attempts: 0 of 4 used Submit