The subs at your local sandwich shop have an average length of 12 inches and a standard deviation of 0.5 inches. Assuming that the lengths are normally distributed, what percentage of the subs that are sold are between 11.5 and 12.5 centimeters in length? 0.3173 0.50 0.6826 0.7854

Respuesta :

Using the normal distribution, it is found that 0.6826 = 68.26% of the subs that are sold are between 11.5 and 12.5 centimeters in length.

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

  • It measures how many standard deviations the measure is from the mean.  
  • After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.

In this problem:

  • The average length is of 12 inches, hence [tex]\mu = 12[/tex].
  • The standard deviation is of 0.5 inches, hence [tex]\sigma = 0.5[/tex].

The proportion of the subs that are sold are between 11.5 and 12.5 centimeters in length is the p-value of Z when X = 12.5 subtracted by the p-value of Z when X = 11.5, hence:

X = 12.5

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{12.5 - 12}{0.5}[/tex]

[tex]Z = 1[/tex]

[tex]Z = 1[/tex] has a p-value of 0.8413.

X = 11.5

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{11.5 - 12}{0.5}[/tex]

[tex]Z = -1[/tex]

[tex]Z = -1[/tex] has a p-value of 0.1587.

0.8413 - 0.1587 = 0.6826

0.6826 = 68.26% of the subs that are sold are between 11.5 and 12.5 centimeters in length.

To learn more about the normal distribution, you can take a look at https://brainly.com/question/24663213