Aset of data with the mean of 60 and the standard deviation of 7.5 is normally distributed what is the -2 standard deviation from the mean

45 is 2 standard deviations below the mean (60).

Step-by-step explanation:

2 standard deviations below the mean is equivalent to what you have written here.

To answer this, start with the mean (60) and subtract 2 standard deviations (2 times 7.5).  Subtract, as indicated:

60 - 2(7.5) = 60 - 15 = 45

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m