The Li family has four children born in different years. Find the probability that a family with four children has exactly two boys and two girls in any order.

Use

$$\log _ { 4 } 3 \approx 0.7925 \text { and } \log _ { 4 } 5 \approx 1.1610$$

to approximate the value of each expression.

$$\log _ { 4 } 15$$

convert the rectangular equation to polar form. Assume a > 0.

$$x^2+y^2=9a^2$$

Express each of the following as a single Fibonacci number. (a)

$$F_{N-2}+F_{N-3}=$$

, (b)

$$F_{N+2}-F_N=$$

, (c)

$$F_{N-3}+F_{N-2}+F_N+F_{N+2}=$$

Simplify by adding, subtracting, multiplying, or dividing as indicated: 5(65¢)

Determine which, if any, of the three statements are equivalent. (a) The grass grows and the trees are blooming. (b) If the trees are blooming, then the grass does not grow. (c) The trees are not blooming or the grass does not grow.

Replace the blank by any of the symbol(s) $\subset, \subseteq, =$ that result in a true statement. If none result in a true statement, write “None of these.” More than one answer may be possible.

$$\{1,2\}\quad {\_}{\_}{\_}{\_}{\_} \quad [\{1\}\cup\{2\}]$$

Evaluate the expression.

$$15 - 4 \sqrt { 36 }$$

An avalanche may occur when the temperature keeps snow crystals from sticking together. The room temperature in an avalanche research lab is -30°C. Scientists study changes in snow crystals by melting snow on a hot plate that heats to only -1°C. In a regular lab, the room temperature is about 18°C and a hot plate heats to about 300°C. How many degrees warmer is the hot plate than the room temperature in each lab? Which difference is greater? How much greater?

Write the expression as a complex number in standard form. (2 -7i)(i+2i)

Add. 34. 13 + (-21) + 16

What is crystallized intelligence? What is fluid intelligence? Which type of intelligence increases with age?

During meiosis, what allows genes located on the same chromosome to separate independently of one another?

Suppose that the moment Kirby hits the ball in Exercise 44 there is a 5-ft/sec split-second wind gust. Assume the wind acts in the horizontal direction out with the ball. If so, by how much does it clear the fence? If not, could the ball be caught?