If x represents the width of the poster (including borders), the area of the finished poster can be written as
.. a = x*(390/(x -10) +8)
.. = 8x +390 +3900/(x -10)
Then the derivative with respect to x is
.. da/dx = 8 -3900/(x -10)^2
This is zero at the minimum area, where
.. x = √(3900/8) +10 ≈ 32.08 . . . . cm
The height is then
.. 390/(x -10) +8 = 8 +2√78 ≈ 25.66 . . . . cm
The poster with the smallest area is 32.08 cm wide by 25.66 cm tall.
_____
In these "border" problems, the smallest area will have the same overall dimension ratio that the borders have. Here, the poster is 10/8 = 1.25 times as wide as it is high.
Given:
The measurement of the angles of a triangle are 3b,2b,and 4b.
To find:
The smallest angle.
Solution:
According to the angle sum property, the sum of all angles of a triangle is 180 degrees.
[Angle sum property]
Divide both sides by 9.
Now,
Therefore, the smallest angle is 40 degrees.
Answer:
a) 40.13% probability that a laptop computer can be assembled at this plant in a period of time of less than 19.5 hours.
b) 34.13% probability that a laptop computer can be assembled at this plant in a period of time between 20 hours and 22 hours.
Step-by-step explanation:
When the distribution is normal, we use 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 question:
a)Less than 19.5 hours?
This is the pvalue of Z when X = 19.5. So
has a pvalue of 0.4013.
40.13% probability that a laptop computer can be assembled at this plant in a period of time of less than 19.5 hours.
b)Between 20 hours and 22 hours?
This is the pvalue of Z when X = 22 subtracted by the pvalue of Z when X = 20. So
X = 22
has a pvalue of 0.8413
X = 20
has a pvalue of 0.5
0.8413 - 0.5 = 0.3413
34.13% probability that a laptop computer can be assembled at this plant in a period of time between 20 hours and 22 hours.
Answer:
Prospective study
Step-by-step explanation:
<em>A cross-sectional study, also known as transverse study, is a type of observational study that analyzes data from a population at a specific point in time.</em> This kind of observation is used if cases cannot be identified a priori or if the prevalence of the disease or condition needs to be determined.
Cohort studies are when two or more groups of subjects are followed over time to see if they develop some disease or if some event occurs, there are two type of cohort studies, prospective and retrospective. <em>Prospective studies (or follow-up studies) follow subjects with different exposures until some point in time where something happens or the study ends</em>, r<em>etrospective studies use historical data</em> to make comparisons based on risk factors or exposures that occurred before the events.
Considering the information given and the observational study exposed to the question, we can conclude that we are talking about a prospective study because data is collected over the next 10 years.
I hope you find this information useful and interesting! Good luck!
