What have scientists inferred from fossil stromatolites?

Use a conversion factor to perform the indicated conversion. 540 seconds to minutes

Find a value of the standard normal random variable $z$, call it $z_0$, such that: $P\left(z \leq z_0\right)=.025$

Define fossil fuel in your own words.

Show that tangent is an odd function.

To what is the illumination of a surface by a light source directly proportional? To what is it inversely proportional?

Let X be a random variable whose value is never zero. Prove or disapprove: E(1/X)=1/E(X).

Find a value of the standard normal random variable $z$, call it $z_0$, such that: $P\left(z \geq z_0\right)=.05$

A wave source recedes from you at $8.2 \mathrm{~m} / \mathrm{s}$, and the wavelength you measure is $20 \%$ greater than what you would measure if the source were at rest. What's the wave speed?

Bargain Department Stores, Inc., is a chain of department stores in the Midwest. Quarterly sales of the "Bargain $8000$-Btu Air Conditioner"' over the past three years are as given in Table $15.7$

Table $15.7$ Air Conditioner Sales and a Dummy Variable Regression Analysis of the Sales Data

$$\begin{array}{lllcclrrrrl} \text {Year } & \text {Quarter} & \text {Sales} & & &\text{Term} & \text{Coef} & \text{SE Coef} & \text{T-Value} & \text{P-Value}\\ 1 & 1 & 2,915 & & & \text{Constant} & 2624.5 & 100.4 & 26.15 & 0.000 & \text{S}=92.4244 \\ & 2 & 8,032 & & & \text{T} & 382.82 & 34.03 & 11.25 & 0.000 & \text{R-Sq}= 100.0\% \\ & 3 & 10,411 & & &\text{TSq} & -11.354 & 2.541 & -4.47 & 0.004 & \text{R-Sq(adj)}=99.9\% \\ & 4 & 2,427 & & &\text{Q2} & 4629.74 & 76.08 &60.86 & 0.000 \\ 2 & 1 & 4,381 & & & \text{Q3} &6738.85 &77.38 &87.09 &0.000\\ & 2 & 9,138 && & \text{Q4} & -1565.32 &79.34 &-19.73 &0.000\\ & 3 & 11,386 \\ & 4 & 3,382 & & & \text{Regression Equation}\\ 3 & 1 & 5,105 & & &\text{Sales}= 1625+383 \text{T} -11.4 \text{TSq} + 4630 \text{Q2} + 6739 \text{Q3} - 1565 \text{Q4}\\ & 2 & 9,894 & & & \text{Time} & \text{Fit} & \text{SE Fit} \text{95\\\% CI} & \text{95\\\% PI}\\ & 3 & 12,300 & & &13 & 5682.4 & 112.6 & (5406.9,5957.9) & (5325.9, 6038.8)\\ & 4 & 4,013 & & & 14 & 10388.4 & 142.8 & (10039.0,10737.8) & (9972.2, 10804.6)\\ & & & & & 15 & 12551.0 & 177.2 (12117.4,12984.7) & (12061.9,13040.2)\\ & & & & & 16 & 4277.7 & 213.9 & (3754.4, 4801.1)& (3707.6,4847.8) \end{array}$$

The right-hand portion of Table $15.7$ is the Minitab output of a regression analysis of the air conditioner sales data using the model in part $a$. $(1)$ Define the dummy variables $Q_2, Q_3$, and $Q_4$. $(2)$ Use the Minitab output to find, report, and interpret the least squares point estimates of $\beta_{Q 2}, \beta_{Q 3}$, and $\beta_{Q 4}$.

It is common practice for some credit card companies to waive a minimum monthly payment (usually for the month of November) as a "holiday gift." Who benefits most from such a waiver-the credit card holder or the credit card company? Explain your reasoning.

Another proposed wheelchair ramp is has an angle of 4$^\circ$ with an adjacent side of 100 inches. What is the rise of this ramp? If necessary, round your answer to the nearest inch.

Work with your team to figure out how many pennies (between 10 and 40) each person could have. Use the clues given below. You may want to use diagrams or expressions to help you determine your answers. Can you find more than one possible answer? a. When Xander arranges his pennies into a rectangle with more than one row, he always has some leftover pennies. When he uses two equal rows or three equal rows, he has one leftover penny. When he arranges them into a rectangle with four equal rows, he has three leftover pennies. b. When Jorge arranges his pennies into a rectangle with two equal rows, three equal rows, or five equal rows, he has one leftover penny. When he arranges his pennies into a rectangle with four equal rows, he has three leftover pennies. How many pennies could Jorge have? c. When Louisa arranges her pennies into a rectangle with two equal rows, three equal rows, four equal rows, or six equal rows, she has one leftover penny. When she arranges her pennies into a rectangle with five equal rows, she has two leftover pennies. How many pennies could Louisa have?

Use a conversion factor to perform the indicated conversion. 360 seconds to minutes.