a golf range has 245 balls. the owner bought a carton of golf balls. how many golf balls does the owner have after buying the ca
1 answer:
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Answer:
The 99% confidence interval is given by ($109.386;$138.613)
Step-by-step explanation:
1) Notation and definitions
n=36 represent the sample size
represent the sample mean
represent the sample standard deviation
m represent the margin of error
Confidence =99% or 0.99
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
2) Calculate the critical value tc
In order to find the critical value is important to mention that we don't know about the population standard deviation, so on this case we need to use the t distribution. Since our interval is at 99% of confidence, our significance level would be given by and
. The degrees of freedom are given by:
We can find the critical values in excel using the following formulas:
"=T.INV(0.005,31)" for
"=T.INV(1-0.005,31)" for
The critical value
3) Calculate the margin of error (m)
The margin of error for the sample mean is given by this formula:
4) Calculate the confidence interval
The interval for the mean is given by this formula:
And calculating the limits we got:
The 99% confidence interval is given by ($109.386;$138.613)
Answer:
= 9
Step-by-step explanation:
The given parameters are;
The point of intersection of the perpendicular bisectors of the sides ,
, and
intersect (meet) at point G
Let D represent the point of intersection of the perpendicular bisector from G to , we have for ΔBGD and ΔCGD;
≅
by reflexive property
∠GDB = ∠GDC = 90° given that is the perpendicular bisector of
Similarly, ≅
, also given that
is the perpendicular bisector of
Therefore;
ΔBGD ≅ ΔCGD by Side-Angle-Side (SAS) rule of congruency
≅
by Congruent Parts of Congruent Triangles are Congruent, (CPCTC)
=
= 9 by definition of congruency
∴ = 9.