a researcher is studying a group of field mice. the distribution of the weight of field mice is approximately normal with mean 25 grams and standard deviation 4 grams. which of the following is closest to the proportion of field mice with a weight greater than 33 grams?

a)0.046
b)0.977
c)0.954
d)0.023​

Respuesta :

Using the normal distribution, it is found that the proportion is closest to 0.023, given by option d.

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Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set 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]

The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

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  • Mean of 25 means that [tex]\mu = 25[/tex]
  • Standard deviation of 4 means that [tex]\sigma = 4[/tex].
  • The proportion above 33 is 1 subtracted by the p-value of Z when X = 33, thus:  

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

[tex]Z = \frac{33 - 25}{4}[/tex]

[tex]Z = 2[/tex]

[tex]Z = 2[/tex] has a p-value of 0.977.

1 - 0.977 = 0.023

Thus the proportion is 0.023, given by option d.

A similar problem is given at https://brainly.com/question/15181104