<em>Answer:</em>
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<em>This " / " means or, btw!</em>
<em>Step-by-step explanation:</em>
<em></em><em></em>
<em>⇒Take square root.</em>
<em></em><em> ± </em>
<em></em>
<em></em><em> or </em>
<em></em>
<em>Hope this helped you!</em>
Answer:
95.64% probability that pledges are received within 40 days
Step-by-step explanation:
Problems of normally distributed samples are 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.
In this problem, we have that:
What is the probability that pledges are received within 40 days
This is the pvalue of Z when X = 40. So
has a pvalue of 0.9564
95.64% probability that pledges are received within 40 days