This measurement tells you how packed in a substance is. The higher the density, the more the object weighs for a certain volumetric unit (such as a cubic meter). Eg: a cubic meter of feathers is likely to weigh less than a cubic meter of solid gold because the feathers have a lot more air in them as opposed to the gold which is more compact.

density = mass/volume is the formula you often use

3 0

3 years ago

A hotel manager believes that 14% of the hotel rooms are booked. If the manager is right, what is the probability that the propo

lara [203]

Answer:

0.4996

Step-by-step explanation:

We are given;

Population proportion; p = 14% = 0.14

Sample size; n = 804

Sample proportion; p^ = 13% = 0.13

Standard deviation; σ = √np(1 - p)

σ = √(804 × 0.14 × (1 - 0.14))

σ = 9.8388

Formula for z-score is;

z = (p^ - p)/σ

z = (0.13 - 0.14)/9.8388

z = -0.01/9.8388

z = -0.001

From online z-score and probability converter attached, we have;

P(Z < -0.001) = 0.4996

5 0

3 years ago

PLEASE ANSWER! DESPERATE, DONT KNOW HOW TO DO IT!

Annette [7]

Answer:

a) x = -7

b) x = -3/2

c) x = -3/2

d) x = 2

e) x = -1

f) x = -2

g) x = 7/3

h) z = -18/5

i) x = 6

Explanation:

The are a couple of rules you should know first.

Negative exponent rule: $a^{-x} = \frac{1}{a^{x}}$

A negative exponent means the same thing as the positive exponent as a denominator under 1.

Exponent to another exponent: $(a^{x})^{n}=a^{xn}$

When raising an exponent to another exponent, you multiply the exponents.

Fraction as a base rule: $(\frac{a}{b})^{x} = \frac{a^{x}}{b^{x}}$

Apply the exponent to the numerator and denominator.

Base 1 rule: $1^{x} = 1$

1 to the power of anything is 1.

Focus on exponents only: $a^{x} = a^{n}\\x = n$

If the bases are the same on both sides of the equation, you can solve for "x" in the exponent by focusing on it only.

Write as an exponent: Rewrite a normal number as an exponent instead. Example: $8=2^{3}$ or $125=5^{3}$

Also, you need to know how to rearrange and simplify formulas to isolate variables (by doing reverse operations in reverse BEDMAS order).

Know how to use the distributive property with brackets, when you multiply each of the terms in the brackets with the term on the outside.

Use each of these rules to solve.

a) $2^{x+4} = \frac{1}{8}$ Write 8 as exponent

$2^{x+4} = \frac{1}{2^{3}}$ Negative exponent rule

$2^{x+4} = 2^{-3}$ Focus on exponents only

$x+4 = -3$ Subtract 4 from each side to isolate

$x = -3-4$

$x = -7$

b) $9^{x}=\frac{1}{27}$ Write 27 as exponent

$9^{x}=\frac{1}{3^{3}}$ Write 9 as exponent

$(3^{2})^{x}=\frac{1}{3^{3}}$ Exponent to another exponent

$3^{2x}=\frac{1}{3^{3}}$ Negative exponent rule

$3^{2x}=3^{-3}$ Focus on exponents only

$2x=-3$ Divide both sides by 2 to isolate

$x=-\frac{3}{2}$

c) $25^{x}=\frac{1}{125}$ Rewrite 125 as exponent

$25^{x}=\frac{1}{5^{3}}$ Rewrite 25 as exponent

$(5^{2})^{x}=\frac{1}{5^{3}}$ Exponent to another exponent

$5^{2x}=\frac{1}{5^{3}}$ Negative exponent rule

$5^{2x}=5^{-3}$ Focus only exponents only

$2x=-3$ Divide both sides by 2 to isolate

$x=-\frac{3}{2}$

d) $7(3^{x})=63$ Divide both sides by 7 to isolate

$3^{x}=63/7$

$3^{x}=9$ Write 9 as exponent

$3^{x}=3^{2}$ Focus on exponents

$x=2$

e) $10^{3x}=0.001$ Write 0.001 as fraction

$10^{3x}=\frac{1}{1000}$ Write 1/1000 as exponent

$10^{3x}=\frac{1}{10^{3}}$ Neg. exponent

$10^{3x}=10^{-3}$ Focus on exponents

$3x=-3$ Divide both sides by -3

$x=-3/3$

$x=-1$

f) $6(\frac{1}{10})^{x}=600$ Divide both sides by 6

$(\frac{1}{10})^{x}=\frac{600}{6}$

$(\frac{1}{10})^{x}=100$ Write 100 as exponent

$(\frac{1}{10})^{x}=10^{2}$ Fraction as base rule

$\frac{1^{x}}{10^{x}}=10^{2}$ Base 1 rule

$\frac{1}{10^{x}}=10^{2}$ Neg. exponent

$10^{-x}=10^{2}$ Focus on exponent

$-x=2$ Divide both sides by -1

$x=-2$

g) $27^{x-3}=(\frac{1}{3})^{2}$ Write 27 as exponent

$(3^{3})^{x-3}=(\frac{1}{3})^{2}$ Exponent to another exponent

$3^{3(x-3)}=(\frac{1}{3})^{2}$ Fraction as base

$3^{3(x-3)}=\frac{1^{2}}{3^{2}}$ Base 1 rule

$3^{3(x-3)}=\frac{1}{3^{2}}$ Neg. exponent

$3^{3(x-3)}=3^{-2}$ Focus

$3(x-3)=-2$ Distribute over brackets

$3x-9=-2$ Add 9 to both sides

$3x=-2+9$

$3x=7$ Div. both sides by 3

$x=\frac{7}{3}$

h) $4^{\frac{2z}{3}} = 8^{z+2}$ Write 4 as exponent

$(2^{2})^{\frac{2z}{3}} = 8^{z+2}$ Exponent to another exponent

$2^{2\frac{2z}{3}} = 8^{z+2}$ Write 8 as exponent

$2^{2\frac{2z}{3}} = (2^{3})^{z+2}$ Exponent to another exponent

$2^{2\frac{2z}{3}} = 2^{3(z+2)}$ Focus

$2\frac{2z}{3} = 3(z+2)$ Multiply whole number with fraction

$\frac{4z}{3} = 3(z+2)$ Distribute

$\frac{4z}{3} = 3z+6$ Multiply both sides by 3

$4z = 3(3z+6)$ Distribute

$4z = 9z+18$ Subtract 9z from both sides

$4z-9z = 18$

$-5z = 18$ Div. both sides by -5

$z = -\frac{18}{5}$

i) $5(2)^{x-1}+3=163$ Subtract 3 on both sides

$5(2)^{x-1}=163-3$

$5(2)^{x-1}=160$ Div. both sides by 5

$(2)^{x-1}=160/5$

$(2)^{x-1}=32$ Write 32 as exponent

$(2)^{x-1}=2^{5}$ Focus

$x-1=5$ Add 1 to both sides

$x=5+1$

$x=6$

5 0

3 years ago