Pls help I put a pic of problem
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Our goal here is to somehow "surgically remove" the repeating part of the number, so let's start by putting the original value in a variable and messing around with it a bit.
We'll let . We want to cut the
bit off completely, so let's create the scalpel that'll let us do that. If
, then we can also say that
. Maybe I was lying a bit: the
is our real scalpel here, and
is where we'll be making the cut. Mathematically, a "cut" is almost always shorthand for subtraction, so let's see what our operation (cutting
off of
) leaves us with:
The operation was a success! We can now simply divide either side by 9 to find , which, when reduced by dividing the numerator and denominator by 3, gives us
According to the Central Limit Theorem, the distribution of the sample means is approximately normal, with the mean equal to the population mean (1.4 flaws per square yard) and standard deviation given by:
The z-score for 1.5 flaws per square yard is:
The cumulative probability for a z-score of 1.11 is 0.8665. Therefore the probability that the mean number of flaws exceeds 1.5 per square yard is
1 - 0.8665 = 0.1335.
The z-score for 1.5 flaws per square yard is:
The cumulative probability for a z-score of 1.11 is 0.8665. Therefore the probability that the mean number of flaws exceeds 1.5 per square yard is
1 - 0.8665 = 0.1335.