# significance level

• May 4th 2009, 04:15 PM
mherr
significance level
880 randomly chosen people surveyed. 493 of them admitted to chewing gum. If we use a signifagant level of 0.01, can we conclude that a majority of people chew gum?
• May 4th 2009, 10:40 PM
matheagle
test $\displaystyle H_0:p=.5$ vs. $\displaystyle H_a:p>.5$

$\displaystyle \hat p=493/880$ the test statistic is $\displaystyle {\hat p -.5\over \sqrt{(.5)(.5)\over 880}}$

the rejection region is $\displaystyle Z>Z_{\alpha}$
• May 4th 2009, 11:30 PM
mherr
Quote:

Originally Posted by matheagle
test $\displaystyle H_0:p=.5$ vs. $\displaystyle H_a:p>.5$

$\displaystyle \hat p=493/880$ the test statistic is $\displaystyle {\hat p -.5\over \sqrt{(.5)(.5)\over 880}}$

the rejection region is $\displaystyle Z>Z_{\alpha}$

I put $\displaystyle \hat p=493/880$ into the formula:

$\displaystyle {(443/880) -.5\over \sqrt{(.5)(.5)\over 880}}=3.573$

is this correct and where do i go from here?

also, where do you use the info about the significance level being = 0.01
• May 5th 2009, 04:58 AM
mr fantastic
Quote:

Originally Posted by mherr
I put $\displaystyle \hat p=493/880$ into the formula:

$\displaystyle {(443/880) -.5\over \sqrt{(.5)(.5)\over 880}}=3.573$

is this correct and where do i go from here? Mr F says: Is z = 3.75 significant?

also, where do you use the info about the significance level being = 0.01 Mr F says: Well, if the significance level is 0.01, what's the value of $\displaystyle {\color{red}z_{\alpha}}$? You're expected to be able to look it up ....

Post #2 gives you the solution, all you have to do is fill in the details. How many lessons have you had on this material?
• May 5th 2009, 05:10 AM
plm2e
z.99 = 2.33