Learning Materials
Features
Discover
Chapter 12: Q. AP4.2 (page 827)
If and P(B)=0.52 and events A and B are independent, what is P(A or B)?
a. 0.1248
b. 0.28
c. 0.6352
d. 0.76
e. The answer cannot be determined from the given information.
The P(A or B) is 0.76
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Click-through rates Companies work hard to have their website listed at the top of an Internet search. Is there a relationship between a website鈥檚 position in the results of an Internet search (1=top position,2=2nd position, etc.) and the percentage of people who click on the link for the website? Here are click-through rates for the top 10 positions in searches on a mobile device:
a. Make an appropriate scatterplot for predicting click-through rate from the position. Describe what you see.
b. Use transformations to linearize the relationship. Does the relationship between click-through rate and position seem to follow an exponential model or a power model? Justify your answer.
c. Perform least-squares regression on the transformed data. Give the equation of your regression line. Define any variables you use.
d. Use your model from part (c) to predict the click-through rate for a website in the 11th position.
Some high school physics students dropped a ball and measured the distance fallen (in centimeters) at various times (in seconds) after its release. If you have studied physics, you probably know that the theoretical relationship between the variables is distance. Which of the following scatterplots would not approximately follow a straight line?
a. A plot of distance versus
b. A plot of versus time
c. A plot of distance versus
d. A plot of ln(distance) versus ln(time)
e. A plot of log(distance) versus log(time)
Marcella takes a shower every morning when she gets up. Her time in the shower varies according to a Normal distribution with mean minutes and standard deviation minutes.
a. Find the probability that Marcella鈥檚 shower lasts between and minutes on a randomly selected day.
b. If Marcella took a minute shower, would it be classified as an outlier by the rule? Justify your answer.
c. Suppose we choose days at random and record the length of Marcella鈥檚 shower each day. What鈥檚 the probability that her shower time is minutes or greater on at least of the days?
d. Find the probability that the mean length of her shower times on these 10 days exceeds minutes.
Park rangers are interested in estimating the weight of the bears that inhabit their state. The rangers have data on weight (in pounds) and neck girth (distance around the neck in inches) for randomly selected bears. Here is some regression output for these data:
Which of the following represents a 95% confidence interval for the slope of the population least-squares regression line relating the weight of a bear and its neck girth?
a.
b.
c.
d.
e.
Killing bacteria Expose marine bacteria to X-rays for time periods from to minutes. Here is a scatterplot showing the number of surviving bacteria (in hundreds) on a culture plate after each exposure time:
a. Below is a scatterplot of the natural logarithm of the number of surviving bacteria versus time. Based on this graph, explain why it would be reasonable to use an exponential model to describe the relationship between the count of bacteria and the time.
b). Here is the output from a linear regression analysis of the transformed data. Give the equation of the least-squares regression line. Be sure to defne any variables you use.
c. Use your model to predict the number of surviving bacteria after minutes.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine