Question

I just need someone to tell me what they get for the test statistic, with their working out, so I know where I am going wrong please.

Answer 1

@agent0smith

Answer 2

this is what I did, it is wrong clearly lol

Answer 3

@Luigi0210 @e.mccormick

Answer 4

@Notamathgenius

Answer 5

I have no clue m8 sorry ;-;

Answer 6

@thomaster

Answer 7

@ybarrap

Answer 8

a) Null Hypotheses: \(\mu = \mu_0\)
Alternative: \(\mu > \mu_0\)

b) Compute the \(t\) value:
$$
\large{
t = \frac{\overline{x} - \mu_0}{s/\sqrt{n}}
}
$$
Where \(\bar{x}=1065\), \(\mu_0=1050\), \(s=19\) and \(n=50\).

c) Compare \(t\) to \(\large T_{critical}\):

\(\large T_{critical}\) at the \(5\text{%}\) level is 1.6766:

see - http://easycalculation.com/statistics/critical-t-test.php

If \(t < T_{critical}\) then the manufacturer's claims are justified because you can not reject the null hypothesis and the difference is likely just due to random variation.

Answer 9

Can you see that? If not, I'll screenshot it for you.

Answer 10

(just in case)

Answer 11

ybarrap that gives me 5.58 on part b, but my lecturer has 1.537, and I don't know how... and considering the critical value is 1.645, 1.537 seems like the more logical answer.

Any idea how I can get to that?

Answer 12

@ybarrap

Answer 13

this is my lecturers answer

Answer 14

I would have to say that the lecturer made an error -- you and I came up with the same result independently. The formula is pretty straight-forward and we all agree on all the other parameters.

Answer 15

Thank you, I have been getting mad at this alot, but I have never had a answer that high on a hypothesis test, I am inclined to believe there is something missing but we did get the same answer so thank you for helping