The paper referenced in the previous exercise also included data for a second radiologist, Radiologist 2. Based on the data from the previous exercise for Radiologist 1 and the data in the accompanying table for Radiologist 2, write a paragraph comparing the accuracy of sex predictions made by these two radiologists.
6.85 Radiologists are often asked to predict the sex of a baby from ultrasound images made during pregnancy. The authors of the paper “The Use of Three Dimensional Ultrasound for Fetal Gender Determination in the First Trimester” (The British Journal of Radiology, [2003]: 448-451) followed up on 159 predictions made by a particular radiologist (Radiologist 1) to determine whether or not they were correct. Data from the paper is summarized in the accompanying table.
- a. Assuming that these data are representative of sex predictions made by Radiologist 1, estimate the
probability that a sex prediction is correct, given that the baby is male. - b. Assuming that these data are representative of sex predictions made by Radiologist 1, estimate the probability that a sex prediction is correct, given that the baby is female.
- c. For Radiologist 1, is a sex prediction more likely to be correct if the baby is male? Explain.
- d. Estimate the probability that a sex prediction made by Radiologist 1 is correct.
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Introduction to Statistics and Data Analysis
- The authors of a paper compared two different instruments for measuring a person's capacity for breathing out air. (This measurement is helpful in diagnosing various lung disorders.) The two instruments considered were a Wright peak flow meter and a mini-Wright peak flow meter. Seventeen people participated in the study, and for each person air flow was measured once using the Wright meter and once using the mini-Wright meter. The Wright meter is thought to provide a better measure of air flow, but the mini-Wright meter is easier to transport and to use. Use of the mini-Wright meter could be recommended as long as there is not convincing evidence that the mean reading for the mini-Wright meter is different from the mean reading for Wright meter. For purposes of this exercise, you can assume that it is reasonable to consider the 17 people who participated in this study as representative of the population of interest. Data values from this paper are given in the accompanying table.…arrow_forwardThe authors of a paper compared two different instruments for measuring a person's capacity for breathing out air. (This measurement is helpful in diagnosing various lung disorders.) The two instruments considered were a Wright peak flow meter and a mini-Wright peak flow meter. Seventeen people participated in the study, and for each person air flow was measured once using the Wright meter and once using the mini-Wright meter. The Wright meter is thought to provide a better measure of air flow, but the mini-Wright meter is easier to transport and to use. Use of the mini-Wright meter could be recommended as long as there is not convincing evidence that the mean reading for the mini-Wright meter is different from the mean reading for Wright meter. For purposes of this exercise, you can assume that it is reasonable to consider the 17 people who participated in this study as representative of the population of interest. Data values from this paper are given in the accompanying table.…arrow_forwardThis obstetrician also wanted to determine the impact that three experimental diets had on the birth weights of pregnant mothers. She was also interested if age had an impact on birth weights. She randomly selected 27 pregnant mothers in the first trimester of whom 9 were 20 to 29 years old, 9 were 30 to 39 years old, and 9 were 40 or older. For each age group, she randomly assigned the mothers to one of three diets. After delivery, she measured the birth weight (in grams) of the babies and obtained the data a) What is the blocking variable?arrow_forward
- This obstetrician also wanted to determine the impact that three experimental diets had on the birth weights of pregnant mothers. She was also interested if age had an impact on birth weights. She randomly selected 27 pregnant mothers in the first trimester of whom 9 were 20 to 29 years old, 9 were 30 to 39 years old, and 9 were 40 or older. For each age group, she randomly assigned the mothers to one of three diets. After delivery, she measured the birth weight (in grams) of the babies and obtained the data a)How many treatments are there? b)What type of design is this? How many replications are there within each cell?arrow_forwardOnly the last 3 sub parts are to be answered iv, v and barrow_forwardMakers of generic drugs are required to show that their generic drugs do not differ significantly from the “reference” or brand name drugs that they imitate. One aspect in which the generic drugs might differ is their extent of absorption in the blood. Twelve subjects were available for the study. Six were randomly selected to receive the generic drug first and then, after a washout period, receive the “reference” drug. The remaining six received the “reference” drug first, followed by the generic drug after the washout period. Suppose the actual p-value for a two-sided test is 0.140. On the basis of this p-value, what should you conclude at α = 0.05? Group of answer choices The mean difference between the absorption rate of the reference drug and the absorption rate of the generic drug is equal to zero There is insufficient evidence to conclude that the mean difference between the absorption rate of the reference drug and the absorption rate of the generic drug is not equal to…arrow_forward
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