Suppose that lengths of newborn girls are normally distributed with a mean of 49.2 cm and a standard deviation of 1.8 cm.Which lengths of female newborns are in the 90th percentile or higher?

Question

daniellelovee · Answer

@kropot72  please help me

amistre64 · Answer

do you have a way to compute a normalCDF function?

amistre64 · Answer

or is this just tables?

daniellelovee · Answer

no sorry just tables

amistre64 · Answer

if we assume your tables are left tailed, then the upper 90 is equal to the lower 10

id start with defining your z score with that is given.

daniellelovee · Answer

ok so μ = 49.2 and σ = 1.8

amistre64 · Answer

$$z_{.0100}=\frac{x-mean}{sd}$$
the table gives you z_{.0100}and you are finding x right?

amistre64 · Answer

you can use z_{.9000} as well if your left tail table goes that high

daniellelovee · Answer

alright sure

amistre64 · Answer

49.2 + 1.8 |z|= x

how do you determine z?

daniellelovee · Answer

would it be 0.90?

amistre64 · Answer

prolly not ...find the closest field value on your table, to .0100  or .9000 and then add the row to the col.
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