Question

Please Help with BOTH

1)

An article reported that for a sample of 56 kitchens with gas cooking appliances monitored during a one-week period, the sample mean CO2 level (ppm) was 654.16, and the sample standard deviation was 163.36. (a) Calculate and interpret a 95% (two-sided) confidence interval for true average CO2 level in the population of all homes from which the sample was selected. (Round your answers to two decimal places.) ppm Interpret the resulting interval. We are 95% confident that this interval contains the true population mean. We are 95% confident that the true population mean lies above this interval. We are 95% confident that this interval does not contain the true population mean. We are 95% confident that the true population mean lies below this interval. (b) Suppose the investigators had made a rough guess of 173 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 54 ppm for a confidence level of 95%? (Round your answer up to the nearest whole number.) kitchens You may need to use the appropriate table in the Appendix of Tables to answer this question.

2)

Answer 1

Soluction Here n=s6, = 6su.16 163-36 difE-S6-1=S5, At 95Y. 2.00y The 95% C-I foru /(63:36 65u.16 t 2.004 11 6su-16 + u3-75 -610.ul, 697-91) we are 95y contidant at thus ntual centauns the Tu pepuaton 1st option moan b hare =173, At 95/-, Z 196 (idth =5u, Tham caid th 2 1-E Sy HE=S 54 - 27 96 (73)- = 157-72 NIS8 Kitchuns 27 bound uppen here z-Value = 0u, then thom 2-tables i0-8508 Ihem he conticdluma lavel padokividty 85%

Givem lowar bound - 1.88 / here z=t183 hamrom 2-tablus probabilaty is 0.97 then Tha confidumie lastel is 977 Guven bound is o.8u M fpen here z0-8u them rom 2-tabluy prstaahiuty s o.80 them he onfidumce lavel is80