Learning Materials
Features
Discover
Chapter 7: Q 48. (page 464)
Decreasing the sample size from to would multiply the standard deviation by
a. 2.
b.
c. 1/2.
d.
e. none of these.
The correct option is (b)
Over 30 million students worldwide already upgrade their learning with Vaia!
All the tools & learning materials you need for study success - in one app.
Get started for free
Warm turkey Tom is cooking a large turkey breast for a holiday meal. He wants to be sure that the turkey is safe to eat, which requires a minimum internal temperature of Tom uses a thermometer to measure the temperature of the turkey meat at four randomly chosen points. The minimum reading is
identify the population, the parameter, the sample, and the statistic.
Bag check Thousands of travelers pass through the airport in Guadalajara, Mexico, each day. Before leaving the airport, each passenger must pass through the customs inspection area. Customs agents want to be sure that passengers do not bring illegal items into the country. But they do not have time to search every traveler's luggage. Instead, they require each person to press a button. Either a red or a green bulb lights up. If the red light flashes, the passenger will be searched by customs agents. A green light means "Go ahead." Customs agents claim that of all travelers will be stopped (red light), because the light has probability of showing red on any push of the button. To test this claim, a concerned citizen watches a random sample of 100 travelers push the button. Only 20 get a red light.
a. Assume that the customs agents' claim is true. Find the probability that the proportion of travelers who get a red light in a random sample of 100 travelers is less than or equal to the result in this sample.
b. Based on your results in part (a), is there convincing evidence that less than of all travelers will be stopped? Explain your reasoning.
refer to the following graph. Here is a dotplot of the adult literacy rates in 177 countries in a recent year, according to the United Nations. For example, the lowest literacy rate was 23.6 %, in the African country of Burkina Faso. Mali had the next lowest literacy rate at 24.0 %.
The overall shape of this distribution is
a. clearly skewed to the right.
b. clearly skewed to the left.
c. roughly symmetric.
d. uniform.
e. There is no clear shape.
Making auto parts Refer to Exercise 54 . How many axles would you need to sample if you wanted the standard deviation of the sampling distribution of to be ? Justify your answer.
Detecting gypsy moths The gypsy moth is a serious threat to oak and aspen trees. A state agriculture department places traps throughout the state to detect the moths. Each month, an SRS of 50 traps is inspected, the number of moths in each trap is recorded, and the mean number of moths is calculated. Based on years of data, the distribution of moth counts is discrete and strongly skewed with a mean of 0.5 and a standard deviation of 0.7.
a. Explain why it is reasonable to use a Normal distribution to approximate the sampling distribution of for SRSs of size 50 .
b. Estimate the probability that the mean number of moths in a sample of size 50 is greater than or equal to 0.6.
c. In a recent month, the mean number of moths in an SRS of size 50 was . . Based on this result, is there convincing evidence that the moth population is getting larger in this state? Explain your reasoning.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Exams 
GCSE 
IGCSE 
AS 
A Level 
International A Level 
University Admissions Tests 
Flashcards 
Vaia AI 
Notes 
Study Plans 
Study Sets 
Find a job 
Find a degree 
Student Deals 
Magazine 
Mobile App