problem set 5


  1. Newborn pressure. A examine takes an SRS from a population of full-engagement infants. The gauge inconsequence of source pressures in this population is 2 pounds. Weigh 95% reliance periods for μ for specimens in which:

a)      n = 81 and = 6.1 pounds

b)      n = 36 and = 7.0 pounds

c)       n = 9 and = 5.8 pounds




  1. SIDS. A specimen of 49 hasty infant engagementination syndrome (SIDS) cases had a moderation source pressure of 2998 g. Installed on other sources in the county, we achieve presume σ = 800 g. Weigh the 95% reliance period for the moderation source pressure of SIDS cases in the county. Interpret your results.




  1. Hemoglobin. Hemoglobin flattens in 11-year-old boys differ according to a Normal classification delay σ = 1.2 g/dL. (a) How catholic a specimen is deficiencyed to treasure moderation μ delay 95% reliance so the room of falsity is no senior than 0.5 g/dL? (b) How catholic a specimen is deficiencyed to treasure μ delay room of falsity 0.5 g/dL delay 99% reliance?




  1. P-treasure and reliance period. A two-sided ordeal of H0: μ = 0 yields a P-treasure of 0.03. Achieve the 95% reliance period for μ enclose 0 in its middle? Achieve the 99% reliance period for μ enclose 0? Explain your forced in each request.



  1. Critical treasures for a t-statistic. The engagement discriminating treasure is repeatedly used to direct to the treasure of a ordeal statistic that determines statistical discernment at some unwandering α flatten for a ordeal. For model, ±1.96 are the discriminating treasures for a two-tailed z-ordeal at α = 0.05.

a)      In performing a t-ordeal installed on 21 observations, what are the discriminating treasures for a one-tailed ordeal when α = 0.05? That is, what treasures of the tstat achieve grant a one-sided P-treasure that is less than or similar to 0.05? What are the discriminating treasures for a two-tailed ordeal at α = 0.05?



  1. Menstrual cycle elongation. Menstrual cycle elongations (days) in an SRS of nine women are as follows: {31, 28, 26, 24, 29, 33, 25, 26, 28}. Use this axioms to ordeal whether moderation menstrual cycle elongation differs significantly from a lunar month. (A lunar month is 29.5 days.) Presume that population treasures differ according to a Normal classification. Use a two-sided opinion. Show all hypothesis-testing steps.




  1. Menstrual cycle elongation. Exercise 6 fitted the moderation elongation of menstrual cycles in an SRS of n = 9 women. The axioms revealed days delay gauge inconsequence s = 2.906 days.

a)      Calculate a 95% reliance period for the moderation menstrual cycle elongation.

b)      Based on the reliance period you lawful fitted, is the moderation menstrual cycle elongation significantly contrariant from 28.5 days at α = 0.05 (two sided)? Is it significantly contrariant from μ = 30 days at the similar α-level? Explain your forced. (Section 10.4 in your citation considered the analogy between reliance periods and discernment ordeals. The similar rules direct less.)




  1. Water fluoridation. A examine looked at the weigh of cavity-free offspring per 100 in 16 North American cities BEFORE and AFTER national impart fluoridation projects. The board adown lists the axioms. You achieve deficiency to manually stamp the axioms into StatCrunch to use that implement to weigh the requested instruction.

a)      Calculate delta treasures for each city. Then erect a stemframe of these differences. Interpret your frame.

b)      What percentage of cities showed an correction in their cavity-free admonish?


c)       Estimate the moderation shift delay 95% reliance.