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BUSI 230 - WEEK 8 TERMINOLOGY
PRACTICE EXAM 2026 LATEST
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
From a random sample of 46 business days, gold prices had a
mean of $1383.85. Assume the population standard deviation is
$202.30. This creates a 90% confidence interval for the
population mean of left parenthesis $1334.79 comma $1432.91
right parenthesis. Does it seem possible that the population mean
could equal the sample mean exactly? Explain. - correct answer -
It would be very unlikely because the margin of error is large
enough that the odds of selecting an exact value is very low.
What do you need to remember when doing math for graphed
confidence problems? - correct answer -The bigger the
confidence value, the bigger the range of the line on the graph.
What formula do we use to find the margin of error E? - correct
answer -E = z꜀ ( σ / √n )
What z꜀ value is equal to 90%? - correct answer -1.645
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What z꜀ value is equal to 95%? - correct answer -1.96
What z꜀ value is equal to 99%? - correct answer -2.575
What equation do we use to find the c-value? - correct answer -(
1/2 ) * ( 1 - ꜀ )
After you find the c-value, what do you do? - correct answer -Plug
c-value in NORM.S.INV, and flip the resulting value from positive
to negative (or negative to positive if it is negative first).
What equation do we use to find the minimum sample size?
(assmuning that - correct answer -n = ( ( z꜀ * σ ) / E ) ^ 2
How do you find the left endpoint of a confidence interval? -
correct answer -x̄ - E
(mean) - (margin of error)
BUSI 230 - WEEK 8 TERMINOLOGY
PRACTICE EXAM 2026 LATEST
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
From a random sample of 46 business days, gold prices had a
mean of $1383.85. Assume the population standard deviation is
$202.30. This creates a 90% confidence interval for the
population mean of left parenthesis $1334.79 comma $1432.91
right parenthesis. Does it seem possible that the population mean
could equal the sample mean exactly? Explain. - correct answer -
It would be very unlikely because the margin of error is large
enough that the odds of selecting an exact value is very low.
What do you need to remember when doing math for graphed
confidence problems? - correct answer -The bigger the
confidence value, the bigger the range of the line on the graph.
What formula do we use to find the margin of error E? - correct
answer -E = z꜀ ( σ / √n )
What z꜀ value is equal to 90%? - correct answer -1.645
, Page | 2
What z꜀ value is equal to 95%? - correct answer -1.96
What z꜀ value is equal to 99%? - correct answer -2.575
What equation do we use to find the c-value? - correct answer -(
1/2 ) * ( 1 - ꜀ )
After you find the c-value, what do you do? - correct answer -Plug
c-value in NORM.S.INV, and flip the resulting value from positive
to negative (or negative to positive if it is negative first).
What equation do we use to find the minimum sample size?
(assmuning that - correct answer -n = ( ( z꜀ * σ ) / E ) ^ 2
How do you find the left endpoint of a confidence interval? -
correct answer -x̄ - E
(mean) - (margin of error)
