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