Answer:
0.3085 = 30.85% probability that a randomly selected pill contains at least 500 mg of minerals
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean 490 mg and variance of 400.
This means that 
What is the probability that a randomly selected pill contains at least 500 mg of minerals?
This is 1 subtracted by the p-value of Z when X = 500. So



has a p-value of 0.6915.
1 - 0.6915 = 0.3085
0.3085 = 30.85% probability that a randomly selected pill contains at least 500 mg of minerals
$216 x 0.08 = $17.28.
Therefore $17.28 was collected for sales tax.
The five digit number, 55,220 contains to 5's and two 2's. The 5's are in the ten thousand and one thousand columns. This means that one five represents 50,000 and the second represents 5, 000. The two's are in the hundreds and tens columns meaning one 2 represents 200 and the other 2 represents 20. In a direct comparison of these numbers the 5's equal 55,000 and the 2's equal 220.
Maury = 120/10 (12 calls/hour)
Tyra = 120/8 (15 calls/hour)
Together they are 27 calls per hour.
120 / 27 = 4.4444444444
So it'd take them 4.44444444 (recurring) hours to make 120 calls.
The formula for the area of a circle is PI x radius^2.
To find the area of the sector, you would multiply the area by the ratio of the the sector angle over 360.
The formula would become PI x r^2 x 30/360.
The 2nd choice is correct.