ISDS 2000 Exam 3

As a point estimate of the population proportion we calculate ________.

- P

one-tailed test

Allows the rejection of the null hypothesis only on one side of the hypothesized value of the population parameter

two-tailed test

Can be rejected on both sides of the hypothesized value of the population parameter

Alternative Hypothesis (Ha)

Contradicts the default state or status quo

Do not reject the null hypothesis and the null hypothesis is true

Correct decision

Reject the null hypothesis and the null hypothesis is false

Correct decision

Null Hypothesis (H0)

Corresponding to a presumed default state of nature or status quo

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200. Which of the following hypothesis tests should be performed?

Left tailed

A company has developed a new diet that it claims will lower one's weight by more that 10 pounds. Heath officials decide to conduct a test to validate this claim. The consumers should be _____________.

More concerned about Type 1 error

For a given sample size, any attempt to reduce the likelihood of making one type of error (Type 1 or Type 2) will increase the likelihood of the other error.

TRUE (reduce type 1, type 2 increases. reduce type 2, type 1 increases.)

A(n) ____________ error is committed when we reject the null hypothesis when the null hypothesis is true.

Type 1

Reject the null hypothesis and the null hypothesis is true

Type 1 error

Do not reject the null hypothesis and the null hypothesis is false

Type 2 error

Consider the following competing hypotheses: Ho:u=0, HA:u≠0. The value of the test statistic is z=-1.38. If we choose a 5% significance level, then we ________.

do not reject the null hypothesis and conclude that the population mean is not significantly different from zero

A binomial distribution can be approximated by a ________ distribution for large sample sizes.

normal

The normal distribution approximation for a binomial distribution is valid when

np ≥ 5 and n(1-p) ≥ 5

The p-value is referred to as the _______.

observed probability of making a type 1 error

E(p)=

p

Reject null hypothesis when...

p<0.05

The expected value of the sampling distribution of P is the

population proportion

Unlike the mean and standard deviation, the population proportion p is a descriptive summary measure that can be used for data that are ______.

qualitative

If the population standard deviation is unknown, it can be estimated by using ______.

s

The null hypothesis tests refers to __________.

the default state of nature

The null hypothesis can only be rejected on _____________.

the left side of the hypothesized mean.

Reject null hypothesis when...

the p-value is less than the significance level.

If the chosen significance level is α = 0.05, then ____________________________________________.

there is a 5% probability of rejecting a true null hypothesis

If we reject the null hypothesis, we conclude that:

there is enough statistical evidence to infer that the alternative hypothesis is true