Sixty percent of the students at a certain school wear neither a ring nor a necklace. Twenty percent wear a ring and 30 percent
wear a necklace. If one of the students is chosen randomly, what is the probability that this student is wearing (a) a ring or a necklace?
1 answer:
Answer:
0.4
Step-by-step explanation:
Given
60 % wear neither ring nor a necklace
20 % wear a ring
30 % wear necklace
This question can be Solved by using Venn diagram
If one person is choosen randomly among the given student the probability that this student is wearing a ring or necklace is
The sum of probabilty is equal to 1 because it completes the set
Therefore the required probabilty is 0.4
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Answer:
a
The 95% confidence interval is
b
Yes there is statistically significant evidence that students in Florida perform differently from other students in the United States
Step-by-step explanation:
From the question we are told that
The population mean is
The sample size is
The sample mean is
The standard deviation is
Given that the confidence level is 95% then the level of significance is mathematically represented as
=>
=>
The critical value for obtained from the normal distribution table is
Generally the margin of error is mathematically represented as
=>
=>
Generally the 95% confidence interval is mathematically represented as
=>
=>
Given that the population mean(1000) is not within the 95% confidence interval for l for the average test score for students in Florida, then it means that there is statistically significant evidence that students in Florida perform differently from other students in the United States