In a kindergarden class of 19 students, 100 addition problems can be completed in a mean time of 6 minutes. The standard deviation is 1 minute. How many students will take between 3 and 9 minutes?

step-by-step explanation:

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.

the answer would be 0.54

2x+60=

step-by-step explanation: