--%>
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 : 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 : OIL I need to product when oil will

    I need to product when oil will finish time (by years) for 6 countries if the keep their production (per day) in the same level. So, the 6 countries have fixed reserves and production 1. statistics for Bahrain Crude oil reserves (million barrels) = 124.6 be careful in million Crude oil producti

    		•
  • 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 : FIN512 Entrepreneurial Finance Chapter

      Chapter 6: Discussion Question: #4 p. 223  It is usually easier to forecast sales for a seasoned firm contrast to an early-stage venture because an early-stage venture has limited access to bank credit lines, sho

    		•
  • Q : Program Evaluation and Review

    Program Evaluation and Review Technique (PERT) A) Developed by US Navy and a consulting firm in 1958 for the Polaris submarine project. B) Technique as for CPM method, but acti

    		•
  • Q : Explain Service times Service times: A)

    Service times:A) In most cases, servicing a request takes a “short” time, but in a few occasions requests take much longer.B) The probability of completing a service request by time t, is independent of how much tim

    		•
  • Q : Designing a system What are the

    What are the questions that comes into mind when designing a system?

    		•
  • Q : Quantities in a queuing system

    Quantities in a queuing system: A: Count of

    		•
  • Q : Decision Variables Determine Decision

    Determine Decision Variables: Let X1 be the number of private homes to be inspectedLet X2 be the number of office buildings to be inspect

    		•
  • Q : STATISTICS Question This week you will

    This week you will analyze if women drink more sodas than men.  For the purposes of this Question, assume that in the past there has been no difference.  However, you have seen lots of women drinking sodas the past few months.  You will perform a hypothesis test to determine if women now drink more

    		•