-2x + 15y = -242x + 9y = 24
1 answer:
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Answer:
<em>Colin spends 1/8 of an hour practicing each song</em>
Step-by-step explanation:
Colin's piano lesson is 3/4 of an hour, long.
In that period, he practices 6 different songs, spending an equal amount of time on each one.
This means that each song gets the sixth part of the lesson duration. The fraction that expresses that amount is:
Colin spends 1/8 of an hour practicing each song
Answer: 11.5%
Explanation:
Since 1 minute = 60 seconds, we multiply 12 minutes by 60 so that 12 minutes = 720 seconds. Thus, we're looking for a probability that the auditor will spend more than 720 seconds.
Now, we get the z-score for 720 seconds by the following formula:
where
So, the z-score of 720 seconds is given by:
Let
t = time for the auditor to finish his work
z = z-score of time t
Since the time is normally distributed, the probability for t > 720 is the same as the probability for z > 1.2. In terms of equation:
Hence, there is 11.5% chance that the auditor will spend more than 12 minutes in an invoice.
Explanation:
Since 1 minute = 60 seconds, we multiply 12 minutes by 60 so that 12 minutes = 720 seconds. Thus, we're looking for a probability that the auditor will spend more than 720 seconds.
Now, we get the z-score for 720 seconds by the following formula:
where
So, the z-score of 720 seconds is given by:
Let
t = time for the auditor to finish his work
z = z-score of time t
Since the time is normally distributed, the probability for t > 720 is the same as the probability for z > 1.2. In terms of equation:
Hence, there is 11.5% chance that the auditor will spend more than 12 minutes in an invoice.