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:
40
Step-by-step explanation:
20 + 2.5x = 3x
20 = 0.5x
x = 40
Answer:
20.41%
Step-by-step explanation:
87.95 - 70 = 17.95
17.95 / 87.95= 0.20409323479
0.20409323479 x 100 = 20.409323479
round it
= 20.41%
Answer:
B. ⅕
Step-by-step explanation:
Fraction of families having more than 2 pets = families with pets of 3 and above ÷ total number of families in the apartment
From the dot plot above, 3 families have 3 pets, and 1 family has 4 pets.
Number of families with more than 2 pets = 3 + 1 = 4
Fraction of families with more than 3 pets = 
For this case we must find the value of the variable "x" of the following expression:

We apply distributive property to the terms within parentheses: 
We subtract 4x on both sides:

We add 2 to both sides:

We divide between 2 on both sides:

Answer:
