So we are given the following system:

Using the first equation again we get:
Answer:
Actual height of the building is 37.5 feet
Step-by-step explanation:
Formula to be used to get the actual length of the building,
Scale used =
= 
By this formula,

Actual height of the building = 1.25 × 30
= 37.5 feet
Therefore, actual height of the building will be 37.5 feet.
Answer:
1.67 meters!
Step-by-step explanation:
First, we can start out by converting centimeters to meters. There are 100 centimeters in a meter, therefore to convert centimeters to meters we divide by 100. 17/100=0.17. Then, to figure out how tall Felicidad was last year, we must work backward, and subtract (because when you grow, you add). 1.84 meters- 0.17 meters= 1.67 meters!
Hope this helped!
Answer:
Standard deviation = 11.30 m/h
Mean = 57.74 m/h
Step-by-step explanation:
Assume that the travel speed is normally distributed.
The corresponding z-score to the 5th and 90th percentile of normal distribution are, respectively, -1.645 and 1.282.
For any given speed X, the z-score is:

If z = -1.645 for X = 39.15 and z= 1.282 for X=72.23, the following system can be solved for the mean and standard deviation of vehicle speed:

The standard deviation is 11.30 m/h and the mean is 57.74 m/h.
#9 . . . #12, and #14: Excellent. All correct, and good estimates.
#13: A very picky comment:
Your math is correct, but the camera can't take 2/3 of an image.
That's why the question asked "How many complete images ...".
After 66 images, there is still some time remaining, but not enough
for another image. So it captures 66 complete images in 3 seconds.
If you are really in elementary school, then I think you're doing
the work of a prodigy. Keep it up ! And best of luck to you.