Answer: Also 57
Step-by-step explanation: You have to round up cause you can't type in decimals.
A stuntman jumping off a 20-m-high building is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film him between 15 m and 10 m above the ground. For which interval of time should the camera film him?
Answer:

Step-by-step explanation:
Given:
A stuntman jumping off a 20-m-high building is modeled by the equation
-----------(1)
A high-speed camera is ready to making film between 15 m and 10 m above the ground
when the stuntman is 15m above the ground.
height
Put height value in equation 1





We know that the time is always positive, therefore 
when the stuntman is 10m above the ground.
height
Put height value in equation 1







Therefore ,time interval of camera film him is 
She can buy 3 because 50-20=30 30/8=3.75 so u round down cause you don't have enough money to buy 4
Answer:
-5
Step-by-step explanation:
-4x +10 =5(x +11)
-4x +10 =5x +55
-4x - 5x =55 - 10
-9x =45
x=-45 :9
x=-5
<u>Answer-</u>
The standard error of the confidence interval is 0.63%
<u>Solution-</u>
Given,
n = 2373 (sample size)
x = 255 (number of people who bought)
The mean of the sample M will be,

Then the standard error SE will be,


Therefore, the standard error of the confidence interval is 0.63%