Vad är z poängen för ett värde som är medelvärdet av en uppsättning data?

z = 0 och P (X< x)="0.5" explanation:="" z="(x-xbar)/sd," where="" xbar="" is="" the="" estimated="" mean="" or="" average="" of="" the="" sample,="" sd="" is="" the="" standard="" deviation,="" and="" x="" is="" the="" value="" of="" the="" particular="" outcome.="" we="" change="" x="" to="" z="" so="" that="" we="" can="" use="" the="" normal="" distribution="" or="" t-tables="" tables,="" which="" are="" based="" on="" a="" zero="" mean="" and="" 1="" standard="" deviation.="" for="" example:="" what="" is="" the="" probability="" that="" the="" mean="" value="" of="" the="" distribution="" is="" 5="" or="" less,="" given="" the="" sample="" average="" is="" 5="" and="" the="" sd="" is="" 2?="" the="" z-score="" would="" be="" (5-5)/2="" which="" is="" equal="" to="" 0.="" the="" probability,="" if="" we="" assume="" the="" normal="" or="" t-distribution,="" is="" 0.50.="" (see="" normal="" distribution="" tables)="" i="" hope="" this="" makes="" sense="" to="" you.="" the="" normal="" distribution="" is="" symmetrical.="" per="" the="" example,="" a="" sample="" average="" of="" 5="" tells="" you="" there="" is="" equal="" chance="" of="" the="" population="" mean="" being="" above="" and="" below="">