Answer:
3 seconds.
Step-by-step explanation:
We have been given that Sandra throws an object straight up into the air with initial velocity of 38 ft per second from platform that is 30 ft above the ground.
To find the time it will take for object to hit the ground, we will use formula:
, where,
represents initial velocity and
represents initial height.
Upon substituting our given initial velocity and initial height, we will get:

We know that object will hit the ground, when height will be 0, so we will equate object's height equal to 0 and solve for t as:

Divide by 2:

Upon using quadratic formula, we will get:






Since time cannot be negative, therefore, it will take 3 seconds for object to hit the ground.
The first one is x=2y plus one.
The second one is
34% of the scores lie between 433 and 523.
Solution:
Given data:
Mean (μ) = 433
Standard deviation (σ) = 90
<u>Empirical rule to determine the percent:</u>
(1) About 68% of all the values lie within 1 standard deviation of the mean.
(2) About 95% of all the values lie within 2 standard deviations of the mean.
(3) About 99.7% of all the values lie within 3 standard deviations of the mean.



Z lies between o and 1.
P(433 < x < 523) = P(0 < Z < 1)
μ = 433 and μ + σ = 433 + 90 = 523
Using empirical rule, about 68% of all the values lie within 1 standard deviation of the mean.
i. e. 
Here μ to μ + σ = 
Hence 34% of the scores lie between 433 and 523.
It neve mentions how much of his farm he uses, but assuming he uses all of it
area=base times height
given
base=4.2
height=3
area=4.2 times 3
area=12.6 square kilometers
answer is 12.6 km²