In step 3, Mark forgot to multiply 5 · 5, so he ended up with 5 in the denominator instead of 5 · 5 = 25
Answer:
maximum height is 4.058 metres
Time in air = 0.033 second
Step-by-step explanation:
Given that the equation height h
h = -212t^2 + 7t + 4
What is the toy's maximum height?
Let us assume that the equation is a perfect parabola
Time t at Maximum height will be
t = -b/2a
Where b = 7 and a = - 212
t = -7/ - 212 ×2
t = 7/ 424 = 0.0165s
Substitute t in the main equation
h = - 212(7/424)^2 + 7(7/424) + 4
h = - 0.05778 + 0.115567 + 4
h = 4.058 metres
Therefore the maximum height is 4.058 metres
How long is the toy in the air?
The object will go up and return to the ground.
At ground level, h = 0
-212t^2 + 7t + 4 = 0
212t^2 - 7t - 4 = 0
You can factorize the above equation and pick the positive time t since time can't be negative
Or
Since we have assumed that it's a perfect parabola,
Total time in air = (-b/2a) × 2
Time in air = 0.0165 × 2 = 0.033 s
I think it does equal x but not really fully sure
Answer:
C. 59.01%
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What percentage of fourth graders are between 50 inches and 56 inches?
This is the pvalue of Z when X = 56 subtracted by the pvalue of Z when X = 50.
X = 56



has a pvalue of 0.8729
X = 50



has a pvalue of 0.2843.
0.8729 - 0.2843 = 0.5886, which is close to 59.01%.
So the correct answer is:
C. 59.01%
Answer:
Ethan plays football 18 minutes each day
Step-by-step explanation:
0.6 : 2.5
75/2.5=30
?/0.6=?
0.6 times 30 since you need then to be proportional
=18 minutes each day for ethan