n a study of 235 adults, the mean heart rate was 82 beats per minute. Assume the population of heart rates is known to be approximately normal with a standard deviation of 5 beats per minute. What is the 98% confidence interval for the mean beats per minute?

Question

ganeshie8 · Answer

Confidence interval =  $\large   \overline{x} \pm  Z^*  \frac{s}{\sqrt{n}}$

ganeshie8 · Answer

you knw :

$\overline{x} = 82$
$s = \mu  = 5$
$n = 235$

ganeshie8 · Answer

find out the $Z^*$ and plugin above^

anonymous · Answer

Oh my head hurts already.

ganeshie8 · Answer

mine too

anonymous · Answer

Oh good so I'm not alone. I'm so close to just guessing and hoping I'm right.

ganeshie8 · Answer

my head hurts cuz urs hurts, not becoz problem is scary :/

anonymous · Answer

My mind was designed for english.

ganeshie8 · Answer

why u doing math ?

anonymous · Answer

I believe the answer is 80.9 – 83.3.   Because I must, I have a duel enrollment test for college on thuresday.

ganeshie8 · Answer

doesnt look right

ganeshie8 · Answer

if u want answer :

$(81.24,   ~82.76)$

ganeshie8 · Answer

it is simple to calculate it on ur own by finding $Z^*$, but u seem to be either in rush or dont wanto learn

anonymous · Answer

I do wan't to learn it, I am just not good at square roots and shy away as soon as I see the square root sign. Kinda like a phobia.

ganeshie8 · Answer

feed it to wolfram friend : http://www.wolframalpha.com/input/?i=82++-+2.33*5%2Fsqrt%28235%29

ganeshie8 · Answer

you're not supposed to do anything by hand - not efficient

ganeshie8 · Answer

just figure out the values, and plug them in ur calculator... nobody takes square roots or divisions by hand... I bet you're allowed a scientific calculator to ur stat exam

anonymous · Answer

Thank you so much. I appreciate your time and I do apoligize if it seemed like all I wan't is a hand out.

ganeshie8 · Answer

np :)