Answer:
15.9% of babies are born with birth weight under 6.3 pounds.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 6.8 pounds
Standard Deviation, σ = 0.5
We are given that the distribution of birth weights is a bell shaped distribution that is a normal distribution.
Formula:
P(birth weight under 6.3 pounds)
P(x < 6.3)
Calculation the value from standard normal z table, we have,

15.9% of babies are born with birth weight under 6.3 pounds.
Answer:
The required confidence inteval = 94.9%.
Step-by-step explanation:
Confidence interval: Mean ± Margin of error
Given: A confidence interval for the true mean diameter of all oak trees in the neighbourhood is calculated to be (36.191, 42.969).
i.e. Mean + Margin of error = 42.969 (i)
Mean - Margin of error = 36.191 (ii)
Adding (i) and (ii), we get

Margin of error = 42.969-39.58 [from (i)]
= 3.389
Margin of error = 
here n= 25 
i.e.

Using excel function 1-TDIST.2T(2.054,24)
The required confidence inteval = 94.9%.
Answer: total length of frame material is 3.2 meters
Step-by-step explanation:
The perimeter of an object or a plane shape is the distance around the object of plane shape.
Mila plans to frame a poster she bought at a concert. The total length of frame material that she needs would be the perimeter of the rectangular frame. The formula for determining the perimeter of a rectangle is expressed as
Perimeter = 2(length + width)
The frame will be rectangular with a base of 0.65 meters and a height of 0.95 meters. Therefore,
Perimeter = 2(0.65 + 0.95)
= 3.2 meters