Question

In: Statistics and Probability

A study on highway safety studied the driving habits of individuals. A sample of 78 cars...

A study on highway safety studied the driving habits of individuals. A sample of 78 cars travelling on the highway revealed an average speed of 94 kph with a standard deviation of 29.9 kph. Determine the 95% confidence interval for the mean speed of all cars (kph), if it is known that speed is normally distributed. Give the upper limit only (in kph) correct to three decimal places.

Solutions

Expert Solution

We have given that,              
              
Sample mean =94      
Sample standard deviation =29.9  
Sample size =78      
Level of significance=0.05      
Degree of freedom =77      
              
t critical value is (by using t table)=   1.99  
              
Confidence interval formula is   

=(87.259,100.741)          
              
              
              

              
Upper confidence limit=   100.741      
              

orchestra answered 2 years ago
Next > < Previous

Related Solutions

A study on highway safety studied the driving habits of individuals. A sample of 78 cars...
A study on highway safety studied the driving habits of individuals. A sample of 78 cars travelling on the highway revealed an average speed of 98.7 kph with a standard deviation of 22.7 kph. Determine the 95% confidence interval for the mean speed of all cars (kph), if it is known that speed is normally distributed. Give the upper limit only (in kph) correct to three decimal places.
The Highway Safety Department wants to study the driving habits of individuals. A sample of 34...
The Highway Safety Department wants to study the driving habits of individuals. A sample of 34 cars traveling on a particular stretch of highway revealed an average speed of 68.8 miles per hour with a standard deviation of 9.8 miles per hour. Round to 4 decimal places. 1.Calculate a 99% confidence interval for the true mean speed of all cars on this particular stretch of highway. ( , ) 2. What sample size is needed to estimate the true average...
The Highway Safety Department wants to study the driving habits of individuals. A sample of 33...
The Highway Safety Department wants to study the driving habits of individuals. A sample of 33 cars traveling on a particular stretch of highway revealed an average speed of 68.2 miles per hour with a standard deviation of 9.2 miles per hour. Round to 4 decimal places. 2. What sample size is needed to estimate the true average speed to within 2.5 mph at 95% confidence? Note: For consistency's sake, round your t* value to 3 decimal places before calculating...
Question 1 The Highway Safety Department wants to study the driving habits of individuals. A sample...
Question 1 The Highway Safety Department wants to study the driving habits of individuals. A sample of 41 cars traveling on the highway revealed an average speed of 60 miles per hour and a standard deviation of 7 miles per hour. The population of car speeds is approximately normally distributed. Determine a 90% confidence interval estimate for the speed of all cars.
A 2017 study selecting a sample of 300 cars traveling daily on a highway revealed that...
A 2017 study selecting a sample of 300 cars traveling daily on a highway revealed that 170 were driven by women. With a significance level of 90% find the confidence interval for the sample indicated. According to a 2010 study, 52 out of every 100 drivers are female. Based on the results of the constructed interval, can you conclude that more women will be driving on the highway in 2017 than indicated in the 2010 study?
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at 40 mph. In the​ institute's 40-mph offset​ test, 40% of the total width of each vehicle strikes a barrier on the​ driver's side. The​ barrier's deformable face is made of aluminum​ honeycomb, which makes the forces in the test similar to those involved in a frontal offset crash between two vehicles of the same​ weight, each going just less than 40 mph. You are...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at 40 mph. In the​ institute's 40-mph offset​ test, 40% of the total width of each vehicle strikes a barrier on the​ driver's side. The​ barrier's deformable face is made of aluminum​ honeycomb, which makes the forces in the test similar to those involved in a frontal offset crash between two vehicles of the same​ weight, each going just less than 40 mph. You are...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at 40 mph. In the​ institute's 40-mph offset​ test, 40% of the total width of each vehicle strikes a barrier on the​ driver's side. The​ barrier's deformable face is made of aluminum​ honeycomb, which makes the forces in the test similar to those involved in a frontal offset crash between two vehicles of the same​ weight, each going just less than 40 mph. You are...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at 40 mph. In the institute’s 40-mph offset test, 40% of the total width of each vehicle strikes a barrier on the driver’s side. The barrier’s deformable face is made of aluminum honeycomb, which makes the forces in the test similar to those involved in a frontal offset crash between two vehicles of the same weight, each going just less than 40mph. You are in...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at...
A highway safety institution conducts experiments in which cars are crashed into a fixed barrier at 40 mph. In the​ institute's 40-mph offset​ test, 40% of the total width of each vehicle strikes a barrier on the​ driver's side. The​ barrier's deformable face is made of aluminum​ honeycomb, which makes the forces in the test similar to those involved in a frontal offset crash between two vehicles of the same​ weight, each going just less than 40 mph. You are...
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT