A certain radioactive isotope is a by-product of some nuclear reactors. Due to an explosion, a nuclear reactor experiences a m
1 answer:
Answer:
73.5%
Step-by-step explanation:
The question is incomplete, the complete question is shown in the image attached.
Half life (t1/2) = 9 days
Time taken (t) = 4 days
From;
0.693/t1/2 = 2.303/t log (No/N)
Substituting values;
0.693/9 = 2.303/4 log(No/N)
0.693/9 × 4/2.303= log(No/N)
2.772/20.727= log(No/N)
Antilog (2.772/20.727)=No/N
1.36 = No/N
Therefore;
N/No = (1.36)^-1
N/No = 0.735
Percentage remaining after 4 days= 0.735× 100= 73.5%
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Answer:
If we compare the p value obtained and the significance level given we have
so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of students reported experiencing excessive daytime sleepiness (EDS) is significantly higher than 0.5 or the half.
Step-by-step explanation:
1) Data given and notation
n=377 represent the random sample taken
X=209 represent the students reported experiencing excessive daytime sleepiness (EDS)
estimated proportion of students reported experiencing excessive daytime sleepiness (EDS)
is the value that we want to test
represent the significance level
Confidence=95% or 0.95
z would represent the statistic (variable of interest)
represent the p value (variable of interest)
2) Concepts and formulas to use
We need to conduct a hypothesis in order to test the claim that the true proportion is higher than 0.5:
Null hypothesis:
Alternative hypothesis:
When we conduct a proportion test we need to use the z statistic, and the is given by:
(1)
The One-Sample Proportion Test is used to assess whether a population proportion is significantly different from a hypothesized value
.
3) Calculate the statistic
Since we have all the info requires we can replace in formula (1) like this:
4) Statistical decision
It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.
The significance level provided . The next step would be calculate the p value for this test.
Since is a right tailed test the p value would be:
If we compare the p value obtained and the significance level given we have
so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of students reported experiencing excessive daytime sleepiness (EDS) is significantly higher than 0.5 or the half.