Answer:
a) 20%
b) 40%
c) Mean = 62.5 seconds; Variance = 52.083 seconds
Step-by-step explanation:
The time it takes a hematology cell counter to complete a test on a blood sample is continuously distributed over the period of 50 to 75 seconds with probability f(x) = 0.04.
a) The percentage of tests require more than 70 seconds is:

b)The percentage of tests that require less than one minute (60 seconds) is:

c) The mean and variance of a continuous distribution are determined by:

Mean = 62.5 seconds.
Variance = 52.083 seconds.
Answer:
Shift 2 unit left
Flip the graph about y-axis
Stretch horizontally by factor 2
Shift vertically up by 2 units
Step-by-step explanation:
Given:
Parent function: 
Transformation function: 
Take -2 common from transform function f(x)
![f(x)=\log[-2(x+2)]+2](https://tex.z-dn.net/?f=f%28x%29%3D%5Clog%5B-2%28x%2B2%29%5D%2B2)
Now we see the step-by-step translation

Shift 2 unit left ( x → x+2 )

Flip the graph about y-axis ( (x+2) → - (x+2) )
![f(x)=\log[-(x+2)]](https://tex.z-dn.net/?f=f%28x%29%3D%5Clog%5B-%28x%2B2%29%5D)
Stretch horizontally by factor 2 [ -x(x+2) → -2(x+2) ]
![f(x)=\log[-2(x+2)]](https://tex.z-dn.net/?f=f%28x%29%3D%5Clog%5B-2%28x%2B2%29%5D)
Shift vertically up by 2 units [ f(x) → f(x) + 2 ]
![f(x)=\log[-2(x+2)]+2](https://tex.z-dn.net/?f=f%28x%29%3D%5Clog%5B-2%28x%2B2%29%5D%2B2)
Simplify the function:

Hence, Using four step of transformation to get new function 
To answer this question, you need to makes the unit of the smartphone screen same. In this case, phone A is using decimal and phone B is using a fraction. You can use which was easier.
Let's try to use decimal. Then you need to convert phone B fraction width into decimal width. The calculation would be: 5cm + 1/3cm= 5 cm + 0.333cm= 5.333cm
From here it clear that phone B has a wider screen than phone A.