A random sample of vehicles n=36 were selected and fitted with a new brake design. a standardized...
A random sample of vehicles n=36 were selected and fitted with a new brake design. a standardized breaking test was then performed on all the vehicles and the stopping distance was recorded. the population stopping distance using this test is a mean of 65 ft with a standard deviation of 12 ft. you find the mean stopping distance for your sample is 60 ft. your job is to determine if the new brake design significantly decreased the stopping distance of these vehicles at an alpha level of .05
1. compute the test statistic (z test) for this sample.
2. what is the z critical value for a one tailed (directional) z test in the negative direction with an alpha = .05
3. what is your statistical decision and conclusion regarding the effectiveness of the new brake design?
Homework Answers
Add Answer to:
A random sample of vehicles n=36 were selected and fitted with a new brake design. a standardized...
A random sample of vehicles n=36 were selected and fitted with a new brake design. a...
A random sample of vehicles n=36 were selected and fitted with a new brake design. a standardized breaking test was then performed on all the vehicles and the stopping distance was recorded. the population stopping distance using this test is a mean of 65 ft with a standard deviation of 12 ft. you find the mean stopping distance for your sample is 60 ft. your job is to determine if the new brake design significantly decreased the stopping distance of...
A random sample of vehicles (n=36) were selected and fitted with a new brake design. A standardized braking test was then performed on all the vehicles and the stopping distances were recorded. The po...
A random sample of vehicles (n=36) were selected and fitted with a new brake design. A standardized braking test was then performed on all the vehicles and the stopping distances were recorded. The population stopping distance using this test is a mean of μ=65 feet with a standard deviation of σ= 12 feet. You find that the mean stopping distance for your sample is 60 feet. Your job is too determine is the new brake design significantly decreased the stopping...
Last fall, a sample of n = 36 freshmen was selected to participate in a new...
Last fall, a sample of n = 36 freshmen was selected to participate in a new 4-hour training program designed to improve study skills. To evaluate the effectiveness of the new program, the sample was compared with the rest of the freshman class. All freshmen must take the same English Language Skills course, and the mean score on the final exam for the entire freshman class was μ = 74.The students in the new program had a mean score of...
A sample of n = 16 individuals is selected from a population with µ = 40...
A sample of n = 16 individuals is selected from a population with µ = 40 and σ = 12, and a treatment is administered to the sample. After treatment, the sample mean is M = 42. You are asked to determine if the sample is still the same as the population. Using an alpha of .05 and a directional (one-tailed) hypothesis because you expect an increase in your sample mean due to the treatment, conduct a one-sample z-test and...
this is a single sample t test problem this is math Assignment #11 Single Sample t-Test...
this is a single sample t test problem
this is math
Assignment #11 Single Sample t-Test What factor determines whether you should use a z-test or a t-test statistic for a hypothesis test? 11.1 A sample is selected from a population mean of u 30. A treatment is administered to the individuals in the sample and, after treatment, the sample mean found to be M 11.2 = 31.3 with a sample variance of s2 9 If the sample consists of...
Given x̅ = 115, µ = 119, σx = 20, and N = 144 conduct a...
Given x̅ = 115, µ = 119, σx = 20, and N = 144 conduct a two-tailed z-test (use sample mean z-score formula). Use α (alpha/criterion) = .05. Be sure to show me the statistical hypotheses (H0 / Ha ) and identify the rejection region (crit), calculate your z-score (obt), and state your conclusion about your z-score. Is it significant or non-significant? Explain why?
A new design for the braking system on a certain type of car has been proposed. For the current system, the true average...
A new design for the braking system on a
certain type of car has been proposed. For the current system, the
true average braking distance at 40 mph under specified conditions
is known to be 120 ft. It is proposed that the new design be
implemented only if sample data strongly indicates a reduction in
true average braking distance for the new design.
(b) Suppose braking distance for the new system is normally distributed with o = 11. Let X...
To test the effectiveness of a treatment, a sample of n = 36 people is selected...
To test the effectiveness of a treatment, a sample of n = 36 people is selected from a normal population with mean of μ = 60. After the treatment is administered to the individuals in the sample, the sample mean is found to be M = 55. (a) If the population standard deviation is σ = 13, can you conclude that the treatment has a significant effect? Use a two-tailed test with α = 0.05. (Round your answers to two...
A new design for the braking system on a certain type of car has been proposed....
A new design for the braking system on a certain type of car has been proposed. For the current system, the true average braking distance at 40 mph under specified conditions is known to be 120 ft. It is proposed that the new design be implemented only if sample data strongly indicates a reduction in true average braking distance for the new design. (a) Define the parameter of interest. μ = true average braking distance for the old design p̂...
For my PSY230 course, I started a new practice of offering extra credit for making an...
For my PSY230 course, I started a new practice of offering extra credit for making an appointment with the Statistics and Methods Lab. The goal is to help students feel more positive toward statistics through one-on-one assistance and therefore feel more comfortable in the course. In order to see if this new element was effective, I compared results from a statistics attitude survey given to my current class to the existing pool of past statistics attitude surveys from all my...
this is a single sample t test problem
this is math
Assignment #11 Single Sample t-Test What factor determines whether you should use a z-test or a t-test statistic for a hypothesis test? 11.1 A sample is selected from a population mean of u 30. A treatment is administered to the individuals in the sample and, after treatment, the sample mean found to be M 11.2 = 31.3 with a sample variance of s2 9 If the sample consists of...
A new design for the braking system on a
certain type of car has been proposed. For the current system, the
true average braking distance at 40 mph under specified conditions
is known to be 120 ft. It is proposed that the new design be
implemented only if sample data strongly indicates a reduction in
true average braking distance for the new design.
(b) Suppose braking distance for the new system is normally distributed with o = 11. Let X...
Most questions answered within 3 hours.
-
Where is the error in this code sequence?
String s1 = "Hello";
String s2 = "ello";...
asked 10 months ago -
Financial data for Joel de Paris, Inc., for last year
follow:
Joel de Paris, Inc.
Balance...
asked 10 months ago -
Consider this reaction:
Al2(SO4)3 (aq)+ BaCl3
(aq) Al2Cl6 (aq)- +
3BaSO4(s) . What is the...
asked 10 months ago -
Suppose that Savneet is considering increasing her
recent random sample from 20 car rentals to 40...
asked 10 months ago -
Trucks arrive at an unloading terminal at an average rate of 120
per hour.
Trucks arrive...
asked 10 months ago -
Why are methanol and ethanol completely soluble in water while
octanol is not very little soluble....
asked 10 months ago -
A facilities manager at a university reads in a research report
that the mean amount of...
asked 10 months ago -
When the CuSO4 is rehydrated by adding water to the anhydrous
compound, is this an endothermic...
asked 10 months ago -
A ray of sunlight is passing from diamond into crown glass; the
angle of incidence is...
asked 10 months ago -
A block of mass 0.249 kg is placed on top of a light, vertical
spring of...
asked 10 months ago -
how do the kidneys compensate in the presences of acidosis
a) trigger hyperventilate
b) reserve acid...
asked 10 months ago -
Question 501 pts
The rental rate of capital to the firm increases. Which of the
following...
asked 10 months ago