According to the National Health Statistics Reports, the standard deviation of the weights of all one-year-old baby boys born in the U. S. is 5.3 pounds. A random sample of 360 one-year-old baby boys born in the U. S. had a mean weight of 25.5 pounds. a) Construct a 90% confidence interval for the mean weight of all one-year-old baby boys in the U. S. Write a sentence that interprets this interval.
b) Should this confidence interval be used to estimate the mean weights of all one-year-old babies in the U. S.? Explain.

A) At 90% confidence interval estimate of the population mean

is,( 25.0405 , 25.9595 )

B) YES

Step-by-step explanation:

Given that,

Point estimate = sample mean  Ж = 25.5

Population standard deviation α  = 5.3

Sample size = n =360

At 90% confidence level the z is ,

∝ = 1 - 90% = 1 - 0.90 = 0.1

∝ / 2 = 0.1 / 2 = 0.05  

Z∝/2 = Z0.05 = 1.645 ( WHEN WE USE THE Z TABLE )

Margin of error E = Z∝/2 * ( α/√n)

E = 1.645 * (5.3 / √360 )  = 0.4595

At 90% confidence interval estimate of the population mean

is

Ж - E < ц < Ж + E  

25.5 - 0.4595 <  ц < 25.5 + 0.4595  

25.0405 <  ц < 25.9595  

( 25.0405 , 25.9595 )

At 90% confidence interval estimate of the population mean

is,( 25.0405 , 25.9595 )

B) This confidence interval can be used to estimate the mean weight of all one - year old babies in the US since the mean value of 25.5 falls within the confidence values, we have sufficient evidence to

conclude that the mean weight of all one-year-old boys is 25.5

the infinity sign

step-by-step explanation:

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )