If a data value in a normal distribution has a negative z-score, which of the following must be true?
the data value must be negative.
the data value must be positive
the data value must be less than the mean.
the data value must be greater than the mean.

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.

i hope this is what you were looking for.

see attached graph