An article reported that for a sample of 46 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 163.7. Required:
a. Calculate and interpret a 9596 (two-sided) confidence interval for true average CO2 level in the population of all homes from which the sample was selected.
b. Suppose the investigators had made a rough guess of 175 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 50 ppm for a confidence level of 95%?

a) CI = ( 148,69 ; 243,31 )

b) n = 189

Step-by-step explanation:

a)  If the Confidence Interval is 95 %

α = 5 %     or   α = 0,05     and   α/2  = 0,025

citical value for α/2  =  0,025     is    z(c) = 1,96

the  MOE   ( margin of error is )  

1,96* s/√n

1,96* 163,7/ √46

MOE =  47,31

Then  CI  =  196 ± 47,31

CI = ( 148,69 ; 243,31 )

CI look very wide ( it sems that if sample size was too low )

b) Now if s (sample standard deviation) is 175, and we would like to have only 50 ppm width with Confidence  level 95 %, we need to make

MOE = 25 = z(c) *  s/√n

25*√n = z(c)* 175

√n   =  1,96*175/25

√n  = 13,72

n = 188,23

as n is an integer number we make n = 189

9) i can't see the angle so whatever it is just do this: cos(angle) x hypotenuse and then use that answer and they hypotenuse and plug it into this: (answer you just got)^2 + b^2 = (hypotenuse)^2. the first answer will be the answer of the adjacent side and the second answer after this equation will be the opposite side.

10) y = 14 x = √147 or 12.12435565

11) x = 4.8

12) x = 4.2

13) x = 9.3

14) pq: 13.2

qr : 17.6

angle p: 53º

15) angle c: 54.3º

angle a: 35.7º

16) h = 21040

v = 1841

step-by-step explanation:

10) 7/sin(30) = 14 = y

7^2 + b^2 = 14^2

49 + b^2 = 196

b^2 = 196 - 49

√b^2 = √147

x = √147

11) cos(70) x 14 = 4.788282007

x = 4.8

12) tan(25) x 9 = 4.196768923

x = 4.2

13) sin(31) x 18 = 9.270685348

x = 9.3

14) pq: sin(37) x 22 = 13.23993051

pq: 13.2

qr: cos(37) x 22 = 17.56998122

qr : 17.6

angle p: 180 - (37 + 90) = 53º

15) cos-1(7/12) = 54.31466529

angle c: 54.3º

angle a: 180 - (90 + 54.31466529) = 35.68533471

angle a: 35.7º

16) 4 x 5280 = 21120

cos(5) x 21120

h = 21039.63202

h = 21040

sin(5) x 21120

v = 1840.729287

v = 1841

what "following statement"?

step-by-step explanation: