Conditions
Stating this, that that 100 Silver Creek students is < 1/10 (of all silver creek students)
What is the 10% condition?
Increasing the sample size does this for a confidence interval
What is decrease variability? or What is to decrease the margin of error and therefore narrow the confidence interval?
This gives a range of plausible values that estimates the true proportion of a population
What is a confidence interval?
invnorm (area: .72, M: 0, Sigma: 1, tail: center)
What is a critical value of z* = +/- 1.08?
The point estimate of a confidence interval (0.35, 0.48)
What is 0.415?
Because you want sampling without replacement to be okay.
What s the 10% condition?
An outcome that is expected to occur less than 5% of the times purely by chance
What is statistically significant?
This 4 step process for writing confidence intervals
What are choose-check-calculate-conclude? or What are state-plan-do-conclude?
invnorm (area: .81, M: 0, Sigma: 1, tail: center)
What is critical value or z* = +/- 1.31?
This margin of error for a confidence interval of (0.432, 0.596)
What is 0.082?
Because you want to generalize results to the larger population.
What is to take a random sample?
They would say I am conservative because I don't have my p-hat
What p-hat = 0.5?
The standard error of a confidence interval
What is the sqrt [p-hat(1-p-hat)/n]?
z* = +/- 1.70
.
What is the critical value for a 91% confidence interval?
[(phat)(1-phat)] / [(ME)/z]^2
What is solving for sample size n?
This the large counts condition for a one sample z-interval for p
What is n*p-hat > 10 and n(1-p-hat) > 10?
0.28 is within the 95 % confidence interval (0.26, 0.40), but that does not mean I am this
What is the true proportion?
0.28 is in the interval (.23, 0.41) so it must be this
What is a plausible value?
This critical value does not include 12% of the standard distribution of data in a normal curve
What is z* = +/-1.55?
invnorm(area: .88, M:0, Sigma: 1, tail: center)
An 80% confidence interval for p-hat = 0.55 and sample size n =88 (round to three decimal places)...assume all conditions are met
What is the confidence interval (0.482, 0.618)?
Because one of the conditions was not met
What is to "proceed with caution"?
0 is within a 95% confidence interval that we believe captures the true difference in proportion of students (9th grade - 12th grade)
What is not convincing evidence? or What is 0 or "no difference" is a plausible value?
This grade wants to attend prom more because the 95% confidence interval estimates the true difference in proportion to be (p_juniors - p_seniors) is (-.21, -0.03)
What are seniors?
The positive of this critical value is at the 96th percentile
What is z* = +1.75?
A 95% confidence interval for difference in (p-hat_1 minus p-hat_2) where p-hat_1 = 0.387 and p-hat_2... .332...sample size n_1 = 364 and sample size n_2 = 367 ...(round to three decimal places)...assume all conditions are met
What is a confidence interval of (-0.014, 0.124)