According to the website www.olx.uz, monthly rent for a two-bedroom apartment has a mean of
$250 and a standard deviation of $100 in the city of Andijan. The distribution of the monthly rent does not
follow the normal distribution. In fact, it is positively skewed. What is the probability of selecting a sample
of 40 two-bedroom apartments and finding the mean to be at least $275 per month?

Respuesta :

Using the normal distribution and the central limit theorem, it is found that there is a 0.0571 = 5.71% probability of selecting a sample  of 40 two-bedroom apartments and finding the mean to be at least $275 per month.

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 mean is of $250, hence [tex]\mu = 250[/tex].
  • The standard deviation is of $100, hence [tex]\sigma = 100[/tex].
  • The sample is of 40 apartments, hence [tex]n = 40, s = \frac{100}{\sqrt{40}}[/tex].

The probability of selecting a sample  of 40 two-bedroom apartments and finding the mean to be at least $275 per month is the p-value of Z when X = 275, hence:

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

By the Central Limit Theorem

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

[tex]Z = \frac{275 - 250}{\frac{100}{\sqrt{40}}}[/tex]

[tex]Z = 1.58[/tex]

[tex]Z = 1.58[/tex] has a p-value of 0.9429.

1 - 0.9429 = 0.0571

0.0571 = 5.71% probability of selecting a sample  of 40 two-bedroom apartments and finding the mean to be at least $275 per month.

You can learn more about the normal distribution and the central limit theorem at https://brainly.com/question/24663213