Turn on thread page Beta
    • Thread Starter
    Offline

    11
    ReputationRep:
    I've been struggling with this question for over two hours today, all the examples on the net seem irrelevant to my actual question. And I have 15 to do! Here is the first one:

    A manufacturer has developed a fishing line that is claimed to have a mean breaking strength of 10kg with a known standard deviation of 0.6kg. Suppose that the breaking strength follows a normal distribution. With a sample size of n=50, the null hypothesis that mu=10kg, against the alternative hypothesis that mu<10kg, will be rejected if the sample mean x(bar)<9.75kg.

    Find the probability of committing a type 1 error.

    I don't even know what to search for apart from 'find probability of committing a type 1 error' in which case I get loads of irrelevant search results. Please help me!
    Offline

    11
    ReputationRep:
    (Original post by epsilondelta)
    I've been struggling with this question for over two hours today, all the examples on the net seem irrelevant to my actual question. And I have 15 to do! Here is the first one:

    A manufacturer has developed a fishing line that is claimed to have a mean breaking strength of 10kg with a known standard deviation of 0.6kg. Suppose that the breaking strength follows a normal distribution. With a sample size of n=50, the null hypothesis that mu=10kg, against the alternative hypothesis that mu<10kg, will be rejected if the sample mean x(bar)<9.75kg.

    Find the probability of committing a type 1 error.

    I don't even know what to search for apart from 'find probability of committing a type 1 error' in which case I get loads of irrelevant search results. Please help me!
    A type 1 error in hypothesis testing means (I think) rejecting the null hypothesis when it is actually true. In this case, it looks as though the probability of committing a type 1 error will be equivalent to the probability of a sample of size n = 50 having a sample mean of <9.75 when the population mean is actually 10.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 5, 2018

University open days

  • University of Exeter
    Undergraduate Open Days - Exeter Campus Undergraduate
    Wed, 24 Oct '18
  • University of Bradford
    Faculty of Health Studies Postgraduate
    Wed, 24 Oct '18
  • Northumbria University
    All faculties Undergraduate
    Wed, 24 Oct '18
Poll
Who do you think it's more helpful to talk about mental health with?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Equations

Best calculators for A level Maths

Tips on which model to get

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.