2.75 x 100 / .20 = 13.75
double check
$13.75 x 0.25 = $2.75
so answer
The bill was $13.75 <span>for lunch before the tip added</span>
Answer:
sqrt62
Step-by-step explanation:
sqrt 62
Answer:
By 71 years of age 80% of the plan participants have passed away.
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 of 68 years and a standard deviation of 4 years.
This means that 
By what age have 80% of the plan participants passed away?
By the 80th percentile of ages, which is X when Z has a p-value of 0.8, so X when Z = 0.84.




By 71 years of age 80% of the plan participants have passed away.