An article contained the following observations on degree of polymerization for paper specimens for which viscosity times concentration fell in a certain middle range:

418 421 421 422 425 428 431 435 437
438 445 447 448 453 458 462 465
(c) Calculate a two-sided 95% confidence interval for true average degree of polymerization. (Round your answers to two decimal places.) Note that it is plausible that the given sample observations were selected from a normal distribution and there are no outliers.

(___ , ___)



Does the interval suggest that 441 is a plausible value for true average degree of polymerization?

Yes or No


Does the interval suggest that 451 is a plausible value?

Yes or No

Respuesta :

Answer:

Step-by-step explanation:

Form a set of values we get

n = 17

And with the help of a calculator

μ₀ = 438,47

σ  = 14,79

Normal Distribution is :  N ( 438,47 ; 14,79 )

c)

CI = 95 % means  α = 5 %    α/2 = 2,5 %    α/2 = 0,025

and as n < 30  we should use t-student distribution with n -1 degree of freedom  df = 16.  t score for 0,025 and 16 s from t-table 2,120

By definition:

CI = [  μ₀  ±  t α/2 ; n-1 * σ/√n ]

CI = [  μ₀  ± 2,120* 14,79/√17 ]

CI = [  μ₀  ±  7,60 ]

CI = [ 438,47 ± 7,60 ]

CI = [  430,87 ; 446,07 ]

95% confidence interval for true average degree of polymerization is  [430.87 ; 446.07] and this interval suggest that 441 is a plausible value for true average degree of polymerization and also this interval does not suggest that 451 is a plausible value.

Given :

  • Sample = [ 418, 421, 421, 422, 425, 428, 431, 435, 437,  438, 445, 447, 448, 453, 458, 462, 465 ]
  • 95% confidence interval.

The total number of values given is, n = 17

Mean, [tex]\mu_0=438.47[/tex]

Standard Deviation, [tex]\sigma = 14.79[/tex]

The normal distribution is given by: N (438.47 ; 14.79)

If Cl  is 95% then [tex]\alpha[/tex] is 5% and [tex]\alpha /2[/tex] is 2.5%

[tex]\alpha /2 = 0.025[/tex]

Now, use t-statistics distribution with (n-1) degree of freedom df = 16

So, the t score for 0.025 and 16 s from t-table 2.120.

[tex]\rm Cl = [\mu_0 \pm t_{\alpha /2};(n-1)\times \dfrac{\sigma}{\sqrt{n} }][/tex]

[tex]\rm Cl = [\mu_0 \pm 2.120\times \dfrac{14.79}{\sqrt{17} }][/tex]

[tex]\rm Cl = [\mu_0 \pm 7.60][/tex]

Cl = [430.87 ; 446.07]

Yes, the interval suggests that 441 is a plausible value for true average degree of polymerization.

No, the interval does not suggest that 451 is a plausible value.

For more information, refer to the link given below;

https://brainly.com/question/2561151