Unit Test — Cumulative exam Answers

A savings account pays 2% interest compounded annually. If $1,200 is deposited initially and again at the first of each year, how much money will be in the account three years after the initial deposit?

Car insurance companies want to keep track of the average cost per claim. The current data in use for Auto Insurance R Us is an average of $2,200 for each claim with a standard deviation of $500. With this average, the company can stay competitive with rates but not lose money. However, the statistician for the company believes that the cost of the average claim has increased. He pulled 40 recent claims and found the average to be $2,350. Which most restrictive level of significance would suggest that the company should raise rates? Upper-Tail Valuesa5%2.5%1%Critical z-values1.651.962.58

The proportions of multiple samples of registered voters who vote are normally distributed, with a mean proportion of 0.38 and a standard deviation of 0.0485. What is the probability that a sample chosen at random has a proportion of registered voters who vote between 0.37 and 0.39? Use the portion of the standard normal table below to help answer the question.zProbability0.000.50000.040.51600.210.58320.370.64430.380.64810.390.65171.000.8413

A student is given that point P(a, b) lies on the terminal ray of angle , which is between radians and 2 radians. The student uses the steps below to find cos . Step 1Find the quadrant in which P(a, b) lies:P(a, b) is in Quadrant IV.Step 2Use the point and the Pythagorean theorem to determine the value of r:, but since r must be positive, .Step 3Determine cos ., where a and b are positive.Which of the following explains whether the student is correct?

A student showed the steps below while solving the equation by graphing.Step 1:Write a system of equations: Step 2: Use the change of base formula to rewrite the equations:Step 3:Graph the two equations:Step 4:Identify the x-value at the point of intersection:In which step did the student make the first error?

What is the solution of ?

The times of all 15 year olds who run a certain race are approximately normally distributed with a given mean = 18 sec and standard deviation = 1.2 sec. What percentage of the runners have times less than 14.4 sec?

Which statement best compares the graphs of and ?

When finding the margin of error for the mean of a normally distributed population from a sample, what is , assuming a confidence level of 74%?

The distribution of the values of a population is shown below, and a simple random sample is drawn from the population. Based on this information alone, can the sample be used to make inferences about the population?

The graph of which function passes through (0,3) and has an amplitude of 3?

If you are given the graph of , how could you graph ?

A circle has a central angle measuring radians that intersects an arc of length 18 cm. What is the length of the radius of the circle? Round your answer to the nearest tenth. Use 3.14 for .

What is the approximate length of arc s on the circle below? Use 3.14 for . Round your answer to the nearest tenth.

Which function has a horizontal asymptote of y = 3?

Which equation has x = 4 as the solution?

What are the domain and range of ?

What is written as a single logarithm?

A company plans to sell embroidered hats for $15 each. The company’s financial planner estimates that the cost, y, of manufacturing the hats is a quadratic function with a y-intercept of 7,920 and a vertex of (150, 9,000). What is the minimum number of hats the company must sell to make a profit?

The number of absences for one week for all students at a high school were compiled, and the probability distribution below was created. What is the probability in any given week that a randomly selected student will be absent no more than one day?Probability DistributionDays Absent: XProbability: P(X)00.7810.1420.0330.014050.04