Midterm 3 Econ

want to use a one tailed test which means p> #, P< #

"drop out rate has decreased"

reject the null hypothesis when it is actually true

A Type I error occurs when we __________.

t35= 2.4 always has to be T so you can cross out any z scores and then it always has to be post so you can scores out anyneggitive numbers

A schoolteacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 9 pCi/L. The school samples the air for 36 days and finds an average concentration of 9.4 pCi/L with a standard deviation of 1 pCi/L. The value of the test statistic is __________.

mutually exclusive

In general, the null and alternative hypotheses are __________.

H0: p ≤ 0.50 and HA: p > 0.50

It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock. A politician claims that the proportion of babies born out of wedlock is increasing. Identify the correct null and alternative hypotheses to test the politician's claim.

one tailed test ho: p> .84 and ha: p<.84

Problem 7- many cities around the United States are installing LED street lights in part to combat crime by improving visibility after dusk. an urban police department claims that the proportion of crimes committed after dusk will fall below the current level of .84 if the led streetlights are installed. specify the null and alternative hypothesis.

ho: p < .47. , ha: p>.47 this is a one tailed test 47 do not prefer competitor vs people who do

The competitor claims that its new blend is preferred by more than 47 percent of consumers to green mountain coffee roasters French roast. which of the following should be used to develop the null and alternativehypothisis to test this claim

first need to calculate the p value because it says greater than it is a right tailed test =(T.DIST.RT(2.42,29)) =.011 conclude that reject the null hypothesis and conclude that the mean iq is greater than 100 p-value =T.DIST.RT(2.42,29) = 0.0110Since p-value < 0.05, reject the null hypothesis.

To test if the mean IQ of employees in an organization is greater than 100, a sample of 30 employees is taken and the value of the test statistic is computed as t29 = 2.42 If we choose a 5% significance level, we __________.

particular population parameter of interest,

We use hypothesis testing to resolve conflicts between two competing hypotheses on a ____and these competing hypotheses are mutually exclusive.

Categorical

What type of variable would necessitate using a hypothesis test of the population proportion rather than a test of the population mean?

If we are unable to reject the null hypothesis, then we maintain business as usual.

Which of the following statements concerning hypothesis testing is true?

the sampling distribution of the sample mean

a hypothesis test regarding the population mean is based on

true

a type one error is committed when we reject the null hypothesis

false

a type two error is made when we reject the null hypothesis and the null hypothesis is actually false

false postive

consider the following hypothesis that relate to the medical field ho: a person is free of disease HA: a person has a disease in this instance, type 1 error is often referred to as

false negative

consider the following hypothesis that relate to the medical field ho: a person is free of disease HA: a person has a disease in this instance, type 2 error is often referred to as

basically saying that you have a false positive which is a type 1 error so there is a 5% probability of accepting a false null hypothesis

if the chosen significance level is a = .05 then

mutually exclusive

in general the null and alternative hypothesis are

reject Ho : we can conclude that the high school dropout rate has decreased

the instatute of education sciences measures the high school dropout rate as the percentage of 16-24 year olds who are not enrolled in school and have not earned a high school credential. Last year the high school dropout rate was 8.1%. A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts. The polling company would like to determine wether the dropout rate has decreased. At a 5% sighngnificance level the design is to

need to calculate the test statistic using z score for this problem to find z score (.065-.081)/SQRT((.081*(1-.081))/1,000) =-1.855447

the instatute of education sciences measures the high school dropout rate as the percentage of 16-24 year olds who are not enrolled in school and have not earned a high school credential. Last year the high school dropout rate was 8.1%. A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts. The polling company would like to determine wether the dropout rate has decreased. At a 5% sighngnificance level the test statistic is ____

both < , > and >, <

which of the following are one tailed tests

mu = 10 and mu cant = 10

which of the following are two tailed tests

Ho: mu=0 , Ha: mu cant = 0 this is a definition of a two tailed test

which of the following represents an appropriate set of hypothesis

false - you just reject or fail to reject the null hypothesis. There is no accepting a hypothesis

on the basis of sample information , we either accept the null hypothesis or reject the null hypothesis

do not reject the null hypothesis when it is actually false

A Type II error occurs when we __________.

the sampling distribution of the sample mean

A hypothesis test regarding the population mean is based on __________.

sampling distribution of the sample mean X with line over

A hypothesis test regarding the population mean µ is based on the

find the test stat exel equation =(2.04-2)/(0.21/SQRT(55)) =1.14260 p-value >0.10 Do not reject H0 since the p-value is greater than significance level. Correct Can you conclude that the machine is working improperly- no you can not

A machine that is programmed to package 2.00 pounds of cereal in each cereal box is being tested for its accuracy. In a sample of 55 cereal boxes, the mean and the standard deviation are calculated as 2.04 pounds and 0.21 pound, respectively. (You may find it useful to reference the appropriate table: z table or ttable)

H0:μ≥$1,200,HA:μ<$1,200

Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200. The correct hypothesis statement would be __________.

since talking about alternative and talking about less this would be ho: p > .47. , ha: p<. 47 one tailed test

Expedia would like to test the average round-trip airfare between Philadelphia and Dublin is less than 1,200 the correct hypothesis statement would be

In exel test stat equals =(10.7-9.1)/(2.1/SQRT(15)) this is a right tailed test p value exel equation =T.DIST.RT(B3,14) its 14 because you need to subtract 1 from 15 =.0052 less than 1 for significance level of 5 percent Reject H0 since the p-value is less than significance level. we conclude jay the population mean is greater than 12.1

In order to conduct a hypothesis test for the population mean, a random sample of 15 observations is drawn from a normally distributed population. The resulting sample mean and sample standard deviation are calculated as 10.7 and 2.1, respectively. (You may find it useful to reference the appropriate table: z table or t table.) H0: μ ≤ 9.1 against HA: μ > 9.1

type 1= .04 type 2=.06 so 4% and 6%

Problem 8- a professional sports organization is going to implement a test for steroids. the tests gives postivereaction in 94 % of the poeple who have taken the steroid. however it enourmusously gives a positive reaction in 4% of the people who have not taken the steroid. what is the probability of Type 1 and type 2 errors giving the null hypothesis " the individual has not taken steriods"

variable is categorical.

The population proportion p is the essential descriptive measure when the ....

cross out the z needs to be a T problem tdf=x− − μos/n√tdf=x− − μos/n its the more simple one the bottom is not all square rooted

When conducting a hypothesis test concerning the population mean, and the population standard deviation is unknown, the value of the test statistic is calculated as __________. ( population mean)

needs to be a z score so cross out t's then its there complicated one with the whole bottom being square rooted

When conducting a hypothesis test concerning the population proportion, the value of the test statistic is calculated as __________ (population proportion)

need to calculate p value (1-NORM.S.DIST(abs(Z),true) =.031

the instatute of education sciences measures the high school dropout rate as the percentage of 16-24 year olds who are not enrolled in school and have not earned a high school credential. Last year the high school dropout rate was 8.1%. A polling company recently took a survey of 1,000 people between the ages of 16 and 24 and found that 6.5% of them are high school dropouts. The polling company would like to determine wether the dropout rate has decreased. At a 5% sighngnificance level the p value =

the mean of the eighth grade reading comprehension test- because we are looking at national average

the national average for an eight grade reading comprehension test is 73. a school district claims that its eithgraders outperform the national average. in testing the school districts claim, how does one define the population parameter of interest?

true

the null hypothesis corresponds to a presumed default state of nature