If EC$2.50 is equivalent to US$1.00, then EC$20.00 in US dollars is?
1 answer:
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Complete Question
The complete question is shown on the first uploaded image
Answer:
a
Yes the researcher can conclude that the supplement has a significant effect on cognitive skill
b
c
The result of this hypothesis test shows that there is sufficient evidence to that the supplement had significant effect.The measure of effect size is large due to the large value of Cohen's d (0.5778 > 0.30 )
Step-by-step explanation:
From the question we are told that
The sample size is n=16
The sample mean is
The standard deviation is
The population mean is
The level of significance is
The null hypothesis is
The alternative hypothesis is
Generally the test statistics is mathematically represented as
=>
=>
Generally the p-value is mathematically represented as
From the z-table
=>
=>
From the obtained values we see that
Decision Rule
Reject the null hypothesis
Conclusion
There is sufficient evidence to conclude that the supplement has a significant effect on the cognitive skill of elderly adults
Generally the Cohen's d for this study is mathematically represented as
=>
=>
Answer: a. The interval in percentage is (23.46% , 30.76%)
b. No
Step-by-step explanation: To determine the confidence interval of a proportion, first find the percentage of yellow in that population:
phat =
phat = 0.2711
The level α is 95%
1 - α = 0.05
α/2 = 0.025
As the population is bigger than 30, use z-test.
According to the table, z-score for α/2 = 0.025 is z = 1.96
The error for the interval is:
E = z.
E = 1.96.
E = 1.96*0.01865
E = 0.0365
The lower and higher limits of the interval are:
phat - E = 0.2711 - 0.0365 = 23.46%
phat + E = 0.2711 + 0.0365 = 30.76%
In conclusion, the 95% confidence interval to estimate the percentage of yellow is (23.46%,30.76%)
b. No, because 25% is inside the interval meaning that it doesn't contradict the expectations.