She purchased 20 tickets and was told that she had a 20% chance of winning. How many tickets were sold?
1 answer:
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Answer:
The point estimate for the proportion is p = 0.4725
The 95% confidence interval for the proportion of non-fatal accidents that involved the use of a cell phone is (0.4236, 0.5214).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
For this problem, we have that:
Point estimate
95% confidence level
So , z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval for the proportion of non-fatal accidents that involved the use of a cell phone is (0.4236, 0.5214).
Answer:
50 pieces
Step-by-step explanation:
1 decimeter = 0.1 meter
Therefore,
Thus, 50 pieces can be cut.