The company has to study 199 machines.
In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean of the set, while a high standard deviation indicates that the values are spread out over a wider range.
It is given that;
Margin of error E = 0.7
Confidence interval 98% = 1-0.98 = 0.02
Standard deviation = 6 hours
Number of MRI machines needed per day n, = [(z alpha/2 * SD)/E]²
Z alpha/2 = 1.645 at alpha = 0.1
Inputting these values into n we have that
[(1.645*6)/0.7]²
= 14.1²
= 198.81 is approximately equal to 199
The company has to study 199 machines.
To know more about standard deviation visit: brainly.com/question/475676
option A i.e. Three-fourths (four-thirds) x = negative 6 (four-thirds).
<u>Step-by-step explanation:</u>
We have , The given expression as Three-fourths x = negative 6 , which can be written as
. Now in order to solve this equation in one step , we must notice that coefficient of x must be 1 but it's
, Let's make coefficient of x as 1 by multiplying both side of equations by 4/3:

⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
Therefore, x= -8 & correct option to solve the equation Three-fourths x = negative 6 for x in one step is <u>option A i.e. Three-fourths (four-thirds) x = negative 6 (four-thirds).</u>
Answer:
D. 13*3^x
Step-by-step explanation:
![3^x +4*3^x^+^1= \\3^x+4*3(3^x)=\\3^x(1+[4*3])=\\3^x(1+12)=\\3^x(13)=\\13*3^x](https://tex.z-dn.net/?f=3%5Ex%20%2B4%2A3%5Ex%5E%2B%5E1%3D%20%5C%5C3%5Ex%2B4%2A3%283%5Ex%29%3D%5C%5C3%5Ex%281%2B%5B4%2A3%5D%29%3D%5C%5C3%5Ex%281%2B12%29%3D%5C%5C3%5Ex%2813%29%3D%5C%5C13%2A3%5Ex)
A(b - c) = d
ab - ac = d
ac = ab - d
c = (ab - d)/a