The distribution of the time it takes for different people to solve a certain crossword puzzle is strongly skewed to the right, with a mean of 30 minutes and a standard deviation of 15 minutes. the distribution of z-scores for those times is

z-scores illustrates how far a data element is, from the mean of the dataset.

Given

--- the mean

--- the standard deviation

z-score is calculated using:

(a) The z-score of the mean

This means that:

So, we have:

(b) The z-score of the standard deviation

This means that:

So, we have:

Hence, the distributions of z-score for the mean and the standard deviation are 0 and -1 respectively.

Read more about z-scores at:

link

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step-by-step explanation:

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.