Hypothesis Testing Basics
When we reject the null and it is true.
What is a Type I error.
What is the critical value for a one tail test with alpha = 0.01 and df = 20?
2.528
What formula will you use when you are running a hypothesis test and the population standard deviation is known?
Z - Test Stat
A researcher claims that the average time spent on social media by teenagers is more than 3 hours per day. A sample of 50 teenagers shows an average time of 3.2 hours with a standard deviation of 0.5 hours. What is the test statistic for this claim?
t49 = 2.83
A trade group predicts that back-to-school spending will average $606.40 per family this year. A teacher feels back to school spending is different. What type of hypothesis test and set it up.
What is a two-tail test.
Ho: μ = 606.40
Ha: μ ≠ 606.40
An advertisement for a popular weight loss clinic suggests that participants in its new diet program lose, on average, more than 10 pounds. A consumer activists decides to test the authenticity of the claim with an alpha value of 0.05. She follows the progress of 18 women who recently joined the weight reduction program. She calculates the mean weight loss of these participants as 10.8 pounds with a standard deviation of 2.4 pounds.
What is the critical value?
1.740
What formula will you use to find a confidence interval where the population standard deviation is known?
Z confidence interval
An advertisement for a popular weight loss clinic suggests that participants in its new diet program lose, on average, more than 10 pounds. A consumer activists decides to test the authenticity of the claim. She follows the progress of 18 women who recently joined the weight reduction program. She calculates the mean weight loss of these participants as 10.8 pounds with a standard deviation of 2.4 pounds.
What is the test stat?
t17 = 1.414
If the p-value for a hypothesis test is 0.0189 and the chosen level of significance is α = 0.01, then the correct conclusion is to:
not reject the null hypothesis
What table would you use for the following: You have a sample size of 15 and the population standard deviation is unknown. The sample standard deviation is 1.5. Assume the distribution is normal.
T-Table
What formula will you use to find a confidence interval where the population standard deviation is unknown?
T- Test stat confidence interval
A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the sample proportion?
0.53
It is generally believed that no more than 0.50 of stray animals are purposely left by their owners. A shelter owner feels this number is increasing. Identify the correct null and alternative hypotheses to test the shelter owner's claim.
H₀: p ≤ 0.50 and Hₐ: p > 0.50
Using the T-table, what is the estimated p-value for a two-tail test with a test stat of 2.06 and df of 20?
0.075
What formula will you use when you are running a hypothesis test and the population standard deviation is unknown?
T-test stat
A sample of 40 people owned an average of 1.35 apple products. It is known from a previous study that the population standard deviation of apple product ownership is 0.63 products. Construct a 95% confidence interval.
[1.15, 1.55]
Complete the equation:
point estimate +/- _____
margin of error
A company claims that their new battery lasts at least 10 hours on average. A sample of 30 batteries shows an average life of 9.5 hours with a standard deviation of 1.2 hours. What is the critical value for a test at a 0.05 level of significance?
1.699
What formula will you use when you are running a hypothesis test for population proportion?
Z proportion test stat.
What is the margin of error with the following information.
sample size = 25
standard deviation = 2.33
alpha = 0.05
round to two decimals
0.96