BUS CH 9,10,14 concept questions
A two-tailed test of the population mean is conducted at a = 0.10 . The calculated test statistic is z = 1.55 and P(Z≥1.55)=0.0606. . The null hypothesis should
not be rejected since the p-value = 0.1212 > 0.10
When testing the p-value is the probability of obtaining a sample mean at least as extreme as the one derived from a given sample, assuming that the ____ hypothesis is true.
null
consider the following competing hypotheses: Ho: u=10 versus Ha: u ≠ 10. If a 95% confidence interval is [15,20], then at the 5% significance level we
reject the null hypothesis and conclude that the population mean appears to differ from 10
we choose a value for a before conducting a hypothesis test
true
in hypothesis testing, two incorrect decisions are possible:
1) do not reject the null hypothesis when it is false(Type II) 2) reject the null hypothesis when it is true
the two equivalent methods to solve a hypothesis test are the
1. critical value approach 2. p-value approach
the p-value approach to hypothesis testing in the correct order
1. specify the null and alternative hypotheses 2. calculate the value of the test statistic and its p-value 3. state the conclusion and interpret results
Specify the competing hypotheses that would be used in order to determine whether the population proportion is greater than 0.35.
Ho: p ≤ 0.35 Ha: p > 0.35
An auditor for a small business wants to test the assumption that the mean value of all accounts receivable differs from $550. She takes a sample of 40 accounts and calculates the sample mean and the sample standard deviation. The null and alternative hypotheses for this test are
Ho: u = $500 Ha: u ≠ $500
Which one of the following is NOT a step we use when formulating the null and alternative hypotheses?
calculate the value of the sample statistic
an important final conclusion to a statistical test is to
clearly interpret the results in terms of the initial claim
Consider the following competing hypotheses: Ho: u=10 versus Ha: u=10 confidence interval is [8.25,11.55], then at the 5% significance level we
do not reject the null hypothesis and conclude that the population mean does not significantly differ from 10
a type error occurs if we do NOT reject the hypothesis when is actually false
false
In general, the null and alternative hypotheses are
mutually exclusive
if we reject the null hypothesis when it is actually false we have committed
no error
the hypothesis denoted by Ho: is the ___ hypothesis and the hypothesis denotes by Ha: is the ___ hypothesis
null, alternative
in a hypothesis test, u0 and p0 are hypothesis values of the ___ mean and the ___ proportion, respectively
population, population
we use hypothesis testing to
resolve conflicts between two competing opinions
if the population standard deviation is unknown, it can be estimated by using ____
s
In Inferential statistics, we use ____ Information to make Inferences about an unknown ____ parameter.
sample, population
the basic principle of hypothesis testing is to assume that
the null hypothesis is true and see if the sample data contradict this assumption
The optimal values of Type I and Type errors require a compromise in balancing the costs of each type of error
true
when performing a hypothesis test on u when ó is known, Ho can never be rejected if
z ≥ 0 for a left-tailed test
we do NOT reject the null hypothesis when the p-value is
≥ a
An auditor for a small company suspects that the mean customer account balances have fallen below $550 per month, the average amount for all customer accounts over the past 5 years. She takes a random sample of 40 accounts and computes the sample mean as $543. State the hypotheses for testing the auditor's claim.
Ho: u ≥ 550 Ha: u < 550
An auditor for a small business wants to determine whether the mean value of all accounts receivable is less than $550. She takes a sample of 40 and computes the sample mean and the sample standard deviation. The null and alternative hypotheses for this test are
Ho: u ≥ 550 Ha: u < 550
Consider the following competing hypotheses: Ho: u=150 versus Ha: u=150 If a 95% confidence interval is [100, 200] , then we cannot reject the null hypothesis at the 5% significance level .
true
for a given sample size n, a Type I error can only be reduced at the expense of a higher Type II error
true
