Cumulative exam four .
[questions & answers]
Which of the following shows the extraneous solution to the logarithmic equation below?
2log5(x+1)=2 - ANSWERS-a.) x=-6
What is the formula for margin of error? - ANSWERS-c.) ME = z*s /sqr n
A scientist calculated the mean and standard deviation of a data set to be u=120 and o=9. She
then found that she was missing one data value from the set. She knows that the missing data
value was exactly 3 standard deviations away from the mean. What was the missing data value?
- ANSWERS-b.) 147
A student showed the steps below while solving the equation mc026-1.jpg by graphing.
Step 1:
Write a system of equations: y1=14; y2=log5(2x-3)
Step 2: Use the change of base formula to rewrite the equations:
y1=log14; y2=log(2x-3)/log5
Step 3: Graph the two equations:
, mc026-4.jpg
Step 4: Identify the x-value at the point of intersection:
x=4.5 - ANSWERS-b.) step 2
What is the range of the function y=ex+1 graphed below? - ANSWERS-d.) y > 1
A gymnastics coach records the scores of a gymnast and develops the probability distribution
below. What is the probability the gymnast scores a 9 or 9.5? - ANSWERS-d.) 0.14
Which system of equations can be graphed to find the solution(s) to 4x2 = x2 - 7? - ANSWERS-c.)
y=4x^2
y=x^2-7
The intensity, or loudness, of a sound can be measured in decibels (dB), according to the
equation l(db)=10log[l/l0], where I is the intensity of a given sound and I0 is the threshold of
hearing intensity. What is the intensity, in decibels, [I(dB)], when l=10^32(l0)? Use a calculator.
Round to the nearest whole number. - ANSWERS-c.) 320
A utility company hires pollsters to knock on random doors in different parts of town to survey
residents about the cost of their electric bill. Would this study be biased? Why or why not? -
ANSWERS-b.) Yes, it is biased. Some of the residents who are surveyed may not want to respond
to someone who knocks at their door.
What is the range of the function f(x) = -2(6x) + 3? - ANSWERS-c.) (-infinity,3)
What is the domain of the function y=ln(x+2)? - ANSWERS-b.) x > -2
What are the solutions to log6(x^2 +8)= 1 + log6(x) - ANSWERS-d.) x=2 and x=4