Eighty percent of students surveyed said they feel more focused after exercising. Nine hundred fifty students were surveyed.
2 answers:
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Answer:
0.3182 = 32.81% probability that a randomly selected acre has between 32647 and 43559 ants.
Step-by-step explanation:
When the distribution is normal, we use 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.
In this question, we have that:
Find the probability that a randomly selectd acre has between 32647 and 43559 ants.
This is the pvalue of Z when X = 43559 subtracted by the pvalue of Z when X = 32647. So
X = 43559:
has a pvalue of 0.5517.
X = 32647:
has a pvalue of 0.2236
0.5517 - 0.2236 = 0.3281
0.3182 = 32.81% probability that a randomly selected acre has between 32647 and 43559 ants.