The mean age at which the population of babies first stand without support is normally distributed with a mean of 13.20 months with a standard deviation of 2.00 months. What is the probability of randomly selecting a sample of 25 children who stood on their own by the average age of 12.2 months or earlier

0.00621

Step-by-step explanation:

We solve the above question using the

Z score formula. This is given as:

z = (x-μ)/σ/√n

where

x is the raw score = 12.20 or earlier

This means x ≤ 12.20

μ is the population mean = 13.20

σ is the population standard deviation = 2

n is the random number of samples = 25

z = 12.2 - 13.2/2/√25

z = -1/2/5

z = -1/0.4

z = -2.5

Probability value from Z-Table:

P(x≤ 12.2) = 0.0062097

Approximately = 0.00621

Therefore, the probability of randomly selecting a sample of 25 children who stood on their own by the average age of 12.2 months or earlier is 0.00621

these sign is used to tell weather the number is greater or less than the number   <   or >     but this sign means its equal =    

hope this you and

step-by-step explanation:

answer: the correct answer is -32

step-by-step explanation: