What is the z-score of a measured value of 0.0034, given \$\mu\$ = 0.0041 and \$\sigma\$ = 0.0008?

x = 0.0034 , \$\mu\$ = 0.0041 , \$\sigma\$ = 0.0008

z-score = \$\frac{x- \mu}{\sigma}\$

Put x = 0.0034 in the formula

z-score = \$\frac{0.0034- \mu}{\sigma}\$

Then substract the mean by substution

z-score = \$\frac{0.0034- 0.0041}{\sigma}\$

z-score = \$\frac{−0.0007}{\sigma}\$

Divide the obtained value by standard devation \$\sigma\$ = 0.0008

z-score = \$\frac{−0.0007}{0.0008}\$

z-score at 0.0034

- 0.875

measured value 0.0034 is less than mean 0.0041

z-score is negative

Answer

A