A phone company charges customers a monthly charge using the equation C = 40 + 0.3m, where is the monthly
1 answer:
Option E
The person used the phone for 20 minutes that month
<em><u>Solution:</u></em>
Given that phone company charges customers a monthly charge using the equation:
C = 40 + 0.3m
Where,
"C" is the monthly charge in dollars
"m" is the number of minutes used by the customer
Someone's monthly charge is $46
To find: number of minutes used by that person
Therefore, given C = 46
Substitute C = 46 in given equation
46 = 40 + 0.3m
40 + 0.3m = 46
0.3m = 46 - 40
0.3m = 6
Thus the person used the phone for 20 minutes that month
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Answer: 2.14 %
Step-by-step explanation:
Given : pH measurements of a chemical solutions have
Mean :
Standard deviation :
Let X be the pH reading of a randomly selected customer chemical solution.
We assume pH measurements of this solution have a nearly symmetric/bell-curve distribution (i.e. normal distribution).
The z-score for the normal distribution is given by :-
For x = 6.74
For x = 6.76
The p-value =
In percent,
Hence, the percent of pH measurements reading below 6.74 OR above 6.76 = 2.14%