--%>
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 : State the hypotheses At Western

    At Western University the historical mean of scholarship examination score for freshman applications is 900. Population standard deviation is assumed to be known as 180. Each year, the assistant dean uses a sample of applications to determine whether the mean ex

    		•
  • Q : Problem on queuing diagram Draw a 

    Draw a queuing diagram for the systems below and describe them using Kendall’s notation: A) Single CPU system <

    		•
  • Q : Assumptions in Queuing system

    Assumptions in Queuing system: • Flow balance implies that the number of arrivals in an observation period is equal to the

    		•
  • Q : Develop the most appropriate regression

    Predicting Courier Costs The law firm of Adams, Babcock, and Connors is located in the Dallas-Fort metroplex.  Randall Adams is the senior and founding partner of the firm.  John Babcock has been a partne

    		•
  • Q : Point of estimate standing data se to

    standing data se to develop a point of estimate

    		•
  • Q : Explain Queuing theory Queuing theory :

    Queuing theory: • Queuing theory deals with the analysis of lines where customers wait to receive a service:

    Q : Principles of data analysis For the

    For the data analysis project, you will address some questions that interest you with the statistical methodology we are learning in class. You choose the questions; you decide how to collect data; you do the analyses. The questions can address almost any topic,

    		•
  • Q : Homework help on Human memory & SPSS

    Effect of Scopolamine on Human Memory: A Completely Randomized Three Treamtent Design (N = 28) Scopolamine is a sedative used to induce sle

    		•
  • 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 : Hw An experiment is conducted in which

    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

    		•