A hospital directed collects data on birth weight of newborn babies born in the maternity ward the Director find that the birth weights are approximately normally distributed with a mean of 3300 grams and a standard deviation of 525 grams the empirical rule states that in a normal distribution 68% of values are within one standard deviation of the mean 95% of values are within two standard deviation of the mean and 99.7% of values are within three standard deviations of the mean based on empirical rule what percent of newborn babies born in the maternity wing of this hospital can be expected to have birth weight greater than 2250 grams

97.5% of newborn babies born in the maternity wing of this hospital can be expected to have birth weight greater than 2250 grams.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

The normal distribution is symmetric, which means that 50% of the values are below the mean and 50% are above.

In this problem, we have that:

Mean of 3300, standard deviation of 525.

What percent of newborn babies born in the maternity wing of this hospital can be expected to have birth weight greater than 2250 grams?

2250 = 3300 - 2*525

2250 is 2 standard deviations below the mean.

Of the 50% of the weights below the mean, 95% are going to be greater than 2250(less than 2 standard deviations of the mean).

Of the 50% of the weights above the mean, 100% are going to be greater than 2250.

So

0.975*100% = 97.5%

97.5% of newborn babies born in the maternity wing of this hospital can be expected to have birth weight greater than 2250 grams.

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

20%

step-by-step explanation: