A quality control analyst has collected a random sample of 12 batteries used in heart pacemakers and she plans to test their voltage level and construct a 95% confidence interval estimate of the mean voltage level for the population of batteries. What requirements must be satisfied in order to construct the confidence interval using the method with the t distribution?

A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before​ treatment, 16   subjects had a mean wake time of 102.0   min. After​ treatment, the 16   subjects had a mean wake time of 78.6   min and a standard deviation of 21.5   min. Assume that the 16   sample values appear to be from a normally distributed population and construct a 95 ​% confidence interval estimate of the mean wake time for a population with drug treatments. What does the result suggest about the mean wake time of 102.0   min before the​ treatment? Does the drug appear to be​ effective? Construct the 95 ​% confidence interval estimate of the mean wake time for a population with the treatment.   nothing   minless than muless thannothing   min ​(Round to one decimal place as​ needed.) What does the result suggest about the mean wake time of 102.0   min before the​ treatment? Does the drug appear to be​ effective?   The confidence interval ▼…

An automobile manufacturer needs to estimate the average highway fuel economy (miles per gallon) for a new truck that will be sold starting next year. A random sample of 63 trucks were tested for highway fuel economy and the sample had a mean of 27.1 miles per gallon with a standard deviation of 1.3 miles per gallon.Using a 95% confidence level, determine the margin of error,E, and a confidence interval for the average highway fuel economy of this new truck. Report the confidence interval using interval notation. Round solutions to two decimal places, if necessary.The margin of error is given by E=.A 95% confidence interval is given by

A study was conducted that measured the total brain volume (TBV) (in mm³) of patients that had schizophrenia and patients that are considered normal. The first table contains the TBV of the non- schizophrenic patients and the second table contains the TBV of schizophrenia patients. Compute a 99% confidence interval for the difference in TBV of non-schizophrenic patients and patients with Schizophrenia. Prior studies say nothing about the equality of variances. Round to the nearest whole number. Total Brain Volume (in mm³) of Non-Schizophrenic Patients 1409670 1528399 1541583 1652404 1668272 1606774 1549862 1497601 1525728 1487617 1556951 1484397 1371703 1472556 1455624 1430001 1297891 1365193 1362972 1542673 1483211 1353428 1371403 1663617 1415307 1756698 1340146 1528697 1673225 1456134 1427036 1144683 Total Brain Volume (in mm³) of Schizophrenia Patients 1348795 1093447 1575546 1183986 1363837 1381758 1265598 1137626 1342077 1339149 1317181 1570744 1409139 1242976 1511787 1171081…

A phase three clinical trail for a new medication proposed to treat depression has 1191 participants. If all these individuals are from the group of individuals who were given the medication and 759 individuals who received the medication experienced improvement in their symptoms of depression, construct a 90% confidence interval for the true proportion of individuals on the medication who experienced improvement in their symptoms of depression.

A study was conducted that measured the total brain volume (TBV) (in mm³) of patients that had schizophrenia and patients that are considered normal. The first table contains the TBV of the non- schizophrenic patients and the second table contains the TBV of schizophrenia patients. Compute a 95% confidence interval for the difference in TBV of non-schizophrenic patients and patients with Schizophrenia. Prior studies say nothing about the equality of variances. Round to the nearest whole number. Total Brain Volume (in mm³) of Non-Schizophrenic Patients 1493670 1505354 1642063 1269967 1520437 1581952 1550295 1549683 1338983 1422347 1492283 1195153 1396509 1478392 1485412 1618109 1459455 1717233 1357073 1576932 1417992 1548420 1484842 1595374 1679448 1569374 1370347 1389635 1396599 1533894 1565016 1340012 Total Brain Volume (in mm³) of Schizophrenia Patients 1274453 1212643 1523072 1543675 1466250 1299458 1283251 1592091 1730346 1074105 1362385 1435833 1603966 1523104 1248181 1424469…

A study of 420097 cell phone users found that 134 of them developed cancer of the brain or nervous system. Prior to this study of cell phone​ use, the rate of such cancer was found to be 0.0427% for those not using cell phones. Complete parts​ (a) and​ (b)   A. Use the sample data to construct a 95​% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.