--%>
Assignment Help - homework help

Sample z test and Sample t test

A random sample X1, X2, …, Xn is from a normal population with mean µ and variance σ2. If σ is unknown, give a 95% confidence interval of the population mean, and interpret it. Discuss the major difference between one sample z test and one sample t test.

E

Expert

Verified

Suppose X1, X2, …, Xn be a random sample from a normal population with mean µ and variance σ2.

Assume that σ is unknown.

Define:

X‾: Sample mean
S: sample standard deviation
n: Sample Size

In this case the population variance is unknown, consequently we use t test for estimation of confidence interval.

A 95 % confidence interval for the population mean is given by:

461_stats1.jpg

here α = 0.05.

Note that if there population variance is known, we have to use normal distribution i.e. Z test instead of t distribution.

   Related Questions in Basic Statistics

  • Q : Define Operational Analysis

    Operational Analysis: • Analysis method based on the measurement of the operational characteristics of the system.

    Q : What is Forced Flow Law Forced Flow Law

    Forced Flow Law: • The forced flow law captures the relationship between the various components in the system. It states that the throughputs or flows, in all parts of a system must be proportional t

    		•
  • Q : Building Models Building Models • What

    Building Models • What do we need to know to build a model?– For model checking we need to specify behavior • Consider a simple vending machine – A custome rinserts coins, selects a beverage and receives a can of soda &bul

    		•
  • Q : Safety and Liveness in Model Checking

    Safety and Liveness in Model Checking Approach; •? Safety: Nothing bad happens •? Liveness: Something good happens •? Model checking is especially good at verifying safety and liveness properties    –?Concurrency i

    		•
  • Q : Networks of queues Networks of queues •

    Networks of queues • Typically, the flow of customers/request through a system may involve a number of different processing nodes.– IP packets through a computer network– Orders through a manufactur

    		•
  • Q : Report on Simple Random Sampling with

    One of my friend has a problem on simple random sampling. Can someone provide a complete Report on Simple Random Sampling with or without replacement?

    		•
  • Q : What is your conclusion The following

    The following data were collected on the number of emergency ambulance calls for an urban county and a rural county in Florida. Is County type independent of the day of the week in receiving the emergency ambulance calls? Use α = 0.005. What is your conclusion? Day of the Week<

    		•
  • Q : Help An experiment is conducted in

    An experiment is conducted in which 60 participants each fill out a personality test, but not according to the way they see themselves. Instead, 20 are randomly assigned to fill it out according to the way they think a parent sees them (i.e. how a parent would fill it out to describe the participant

    		•
  • Q : Regression Analysis 1. A planning

    1. A planning official in the Texas Department of Community Affairs, which works in the office next to you, has a problem. He has been handed a data set from his boss that includes the costs involved in developing local land use plans for communities wi

    		•
  • Q : Derived quantities in Queuing system

    Derived quantities in Queuing system: • λ = A / T, Arrival rate • X = C / T, Throughput or completion rate • ρ =U= B / T, Utilization &bu

    		•