The most recent poll of 50 randomly-selected members of a school club with a total of 80 members showed that 38 are planning to
2 answers:
Answer with Explanation:
Total number of members in School Club = 80 members
Number of member randomly Selected,that is sample size used (P) = 50 members
Number of members who are planning to vote for Talia = 38 members
Z Score for 95% confidence interval =1.96
it is given that Margin of Error ,E,of the poll using a 95% confidence interval=12%
Standard Deviation=4.3 (approx)
→95% confidence level for students who are planning to vote for Talia as president of the club lie between → 38 + 4.3 = 42.3 to 38 -4.3=33.7.
→So, members which will vote for Talia as president of the club lies between minimum of 33 members and maximum of 42 members.
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Answer:
C. unlikely
Step-by-step explanation:
Problems of normally distributed samples can be 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.
A probability is said to be extremely likely if it is 95% or higher, and extremely unlikely if it is 5% or lower. A probabilty higher than 50% and lower than 95% is said to be likely, and higher than 5% and lower than 50% is said to be unlikely.
In this problem, we have that:
How likely is it that a single survey would return a mean of 30%?
We have to find the pvalue of Z when X = 0.30.
has a pvalue of 0.1587.
So the correct answer is:
C. unlikely