Question

According to statistics reported by CNBC a surprising number of motor vehicles are not covered by insurance. sample results consistent with the CNBC report showed that in a sample of 300 vehicles 54 were not covered by insurance.

a) Use the data above to develop a 90 percent confidence interval for the actual proportion of vehicles that are not covered by insurance and give the margin of error

. b) Use the p- value approach to determine whether the proportion of all vehicles without insurance is significantly less than 25%

c) Use the p- value approach to determine whether the proportion of all vehicles with insurance is significantly less than 25%

Answer 1

Saupie Stze (30 300 (A) 90% Cowliden ce luternal ter actual vekides net cowor by се 1 ะ 0.18 0.036 .1442 &16 ะ 0.036 Atterwatne kuhdunesia (Hı): -Test statistic (z) = p-10 トく0.RS 0. 18-0. 25 0.85 0.75 0 ,085 300 p-value associ ated urthz壶=-2.8 0.00856 Scritica!ニ乂ニ0.05 because tus。 One-Tailed Test

valuepoitial Hence we rjest Ho Thore i suft ia'eut evialence to covelude than 25% velhicles | (c) 。Saunple fh冲ottont , 300 Null tudhatn esto (Mo):ト025 Attornatrve Test statist,C Cz)= b -po 0.8 2-0.85 0.0RS 0 850.75 ualue associated uuth Zr 22.8 that on d all velhidles with 了wurainen sev nip cantly lead.tma. A 25%