Chris spent half of his money on a pair of headphones. Then he spends half of his remaining money of recordable CDs. Finally, he
2 answers:
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Answer:
z = 10
Step-by-step explanation:
The value of the z-statistic is given by:
In which:
X is the measured value.
is the expected value.
is the standard deviation of the sample.
is the standard deviation of the population.
In this question:
The mean length was 2.9 inches, and the population standard deviation is 0.1 inch.
This means that
Random sample of 100 screws.
This means that n = 100.
To see if the batch of screws has a significantly different mean length from 3 inches, what would the value of the z-test statistic be?
3 inches, so
Answer:
99.87% of the store’s total delivery orders will be delivered to consumers with charge
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:
If a pizza store’s policy is, "Orders delivered within one hour or they’re free!", what percentage of the store’s total delivery orders will be delivered to consumers with charge?
Within one hour, which is 60 minutes. So this is the pvalue of Z when X = 60.
has a pvalue of 0.9987
99.87% of the store’s total delivery orders will be delivered to consumers with charge