A mandatory competency test for high school sophomores has a normal distribution with a mean of 400 and a standard deviation of
1 answer:
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Answer:
20 dimes and 2 quarters
Step-by-step explanation:
x = number of dimes
y = number of quarters
minimum is greater than or equal to ≥
x+y ≥16
no more than is less than or equal to ≤ ,
value of dime is $ 0.10
value of quarter is $0.25 so
0.10x + 0.25y ≤ 3.00
Rewrite inequalities in terms of y:
y ≥16 - x
(0.25/0.25)y ≤ (3.00/0.25)-(0.10/0.25)x→
y≤12 - 0.4x
Graph system: see file
Answer:
Tuesday z-score was 3.26.
Tuesday was a significantly good day.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
A score is said to be significantly high if it has a z-score higher than 1.64, that is, it is at least in the 95th percentile.
In this problem, we have that:
On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z-score.
This is Z when
Tuesday z-score was 3.26.
Was Tuesday a significantly good day?
A z-score of 3.26 has a pvalue of 0.9994. So only 1-0.9994 = 0.0006 = 0.06% of the day are better than Tuesday.
So yes, Tuesday was a significantly good day.