Try another similar question Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P2, the 2-percentile. This is the temperature reading separating the bottom 2% from the top 98%.

Respuesta :

Answer:

P2 = -2.054ºC

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

[tex]\mu = 0, \sigma = 1[/tex]

P2

X when Z has a pvalue of 0.02. So X when Z  = -2.054.

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

[tex]-2.054 = \frac{X - 0}{1}[/tex]

[tex]X = -2.054[/tex]

P2 = -2.054ºC