Determine the approximate sample size to achieve the specied goal in each of the following cases. . You want to estimate the proportion of domestic 1water supply 1wells in Clay County, Mim1esota with arsenic concentrations that exceed the federal drinking water standard for arsenic, which is 10 micrograms per liter. From previous studies you anticipate that the proportion will be around 20%. Your goal is for the 95% condence interval for the proportion to be approximately plus or minus Ul. . A manufacturer of a new concrete anchor claims that their product meets the ductilityr requirements (for both elongation and reduction in area} specied by AC] 313. The installed cost of this new anchor is 25percent less than the anchors that you usuallyr specify, so this new anchor is an interesting product. The manufacturer claims that 99.5% of their anchors will pass the appropriate test. Your goal is for the 95% con dence interval Jr the proportion to be approximately plus or minus 01201 (Le. plus or minus 0.1%). . You want to estimate the proportion of vehicles that exceed 30 miles per hour in the northbound lanes ofI35 at the Iow/hmmsota border between 9:00 p.m. and 6:00 a.m. on weekday nights (Monday through Thursday) when the road conditions are good. Your goal is for the 95% condence interval for the proportion to be approximately plus or minus 0.01. . In 2015 there were apprmtimately 10.13 fatalities per billion vehitle miles travelled in the U.S. It is estimated that within 20 years half of the vehicles on the road will be fully autonomous (Le. ch'ivcrlessT with no steering wheel}. Advocates claim that autonomous vehicles will cut the fatality rate by a factor of 10 - i.e, 1 fatality per billion autonomous vehicle miles travelled in the US. Approximately how many autonomous vehicle fatalities will have to be recorded before we can estimate the rate with a 95% condence interval of plus or minus 0.1 fatality per billion autonomous whicle miles travelled? . The City of Minneapolis wants to estimate the rate of mere pot holes [i.e. severe pot holes per lane mile) on non-arterial city streets this Spring. They do not warn to hazard a guess as this rate, but they want you to design an inexpensive campaign to make an accurate estimate. Approximately how many severe pot holes will need to be located to estimate the rate so that the 95% condence interval is approximately plus or minus 1 severe pot hole per mile