Today the 6th graders had 5 students absent, the 7th graders had 8 students absent,and the 8th graders had 9 students absent. If
1 answer:
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Answer:
The second choice: Approximately of the pretzel bags here will contain between 225 and 245 pretzels.
Step-by-step explanation:
This explanation uses a z-score table where each entry has two decimal places.
Let represent the mean of a normal distribution of variable
. Let
be the standard deviation of the distribution. The z-score for the observation
would be:
.
In this question,
.
.
Calculate the z-score for and
. Keep in mind that each entry in the z-score table here has two decimal places. Hence, round the results below so that each contains at least two decimal places.
.
.
The question is asking for the probability (where
is between two values.) In this case, that's the same as
.
Keep in mind that the probabilities on many z-table correspond to probability of (where
is no greater than one value.) Therefore, apply the identity
to rewrite
as the difference between two probabilities:
.
Look up the z-table for and
:
.
.
.