To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. the maximum penetration (in mils) for each specimen is then measured, yielding a sample average penetration of x = 53.6 and a sample standard deviation of s = 4.9. the conduits were manufactured with the specification that true average penetration be at most 50 mils. they will be used unless it can be demonstrated conclusively that the specification has not been met. what would you conclude? (use α = 0.05.) state the appropriate null and alternative hypotheses. h0: μ ≠ 50 ha: μ > 50 h0: μ = 50 ha: μ ≠ 50 h0: μ > 50 ha: μ = 50 h0: μ = 50 ha: μ > 50

An electronics manufacturer wants to know if customers would be interested in a detachable keyboard for their tables and if so, what the most important features would be. the manufacturer partners with an electronics store to include copies of the survey with every purchase at that store for one week. which of the following best explains why this random sample is unlikely to be a good representative sample of tablet owners' preferences for a detachable keyboard? a) one week is likely not enough time to get a large enough sample. b) most people won't bother to send in the survey, which is likely to skew the results c) there is no way to verify whether the responders to the survey actually own a tablet d) the survey is biased because it was conducted through an electronics store, not the general population

Quadrilateral wxyz is on a coordinate plane. segment yz is on the line x+y=7 and segment xw is on the line x+y=3. which statement proves how segments yz and xw are related

Mozart lenses inc. recently introduced seelites, a thinner lens for eyelasses. of a sample of 800 eyeglass wearers, 246 said they would purchases their next pair of eyeglasses with the new lenses. lenses inc. estimates that the number of people who purchase eyeglasses in a year is 1,700,000. most eyeglasses wearer buy one new pair of eyeglasses a year. what is the annual sales potential for the new lenses.