This is precalculus, please do not answer if you do not understand

In an article in Marketing Science, Silk and Berndt investigate the output of advertising agencies. They describe ad agency outp

fredd [130]

Answer: (7.27%, 7.55%)

Step-by-step explanation:

As per given , we have

Sample size : n= 392

Sample mean : $\overline{x}=7.41\%$

$\sigma=1.43\%$

Critical two-tailed z-value for 95% confidence = $z_{\alpha/2}=1.96$

Required confidence interval would be :

$7.41\%\pm (1.96)\dfrac{1.43\%}{\sqrt{392}}\\\\=7.41\%\pm 0.14\%\\\\=(7.27\%, 7.55\%)$

Hence, the required 95% confidence interval for the mean percentage share of billing volume from network television for the population of all U.S. advertising agencies : (7.27%, 7.55%)

7 0

4 years ago

Which is the range of the function f(x) =One-seventh(9)x?

shutvik [7]

Answer:

Option c: all real numbers greater than 0

Step-by-step explanation:

we have

$f(x)=\frac{1}{7}(9^{x})$

This is a exponential function of the form

$f(x)=a(b^{x})$

where

a is the initial value (y-intercept)

b is the base

r is the rate

b=(1+r)

In this problem we have

a=1/7

b=9

r=b-1 ----> r=9-1=8 -----> r=800%

using a graphing tool

see the attached figure

The domain is the interval ------> (-∞,∞)

The domain is all real numbers

The range is the interval ---------> (0,∞)

The range is all real numbers greater than zero

6 0

3 years ago

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Sin 1 + sin 2 + sin3 .................+ sin 360 = ?

lesya [120]

Assuming that arcs are given in degrees, call S the following sum:

S = sin 1° + sin 2° + sin 3° + ... + sin 359° + sin 360°

Rearranging the terms, you can rewrite S as

S = [sin 1° + sin 359°] + [sin 2° + sin 358°] + ... + [sin 179° + sin 181°] + sin 180° +
+ sin 360°

S = [sin 1° + sin(360° – 1°)] + [sin 2° + sin(360° – 2°)] + ...+ [sin 179° + sin(360° – 179)°]
+ sin 180° + sin 360° (i)

But for any real k,

sin(360° – k) = – sin k

then,

S = [sin 1° – sin 1°] + [sin 2° – sin 2°] + ... + [sin 179° – sin 179°] + sin 180° + sin 360°

S = 0 + 0 + ... + 0 + 0 + 0 (... as sin 180° = sin 360° = 0)

S = 0

Each pair of terms in brackets cancel out themselves, so the sum equals zero.

∴ sin 1° + sin 2° + sin 3° + ... + sin 359° + sin 360° = 0 ✔

I hope this helps. =)

Tags: <em>sum summatory trigonometric trig function sine sin trigonometry</em>

4 0

3 years ago

Triangle ABC contains side lengths b=3 inches and c= 5 inches in two or more sentences describe whether or not it is possible fo

Scrat [10]

Answer:

Since sine of all angles are always less than one, this shows there is no possible way to have an angle C. Thus it is impossible to have a triangle ABC with the given properties of side lengths b=3 inches and c= 5 inches to have angle B =45 degrees.

Step-by-step explanation:

In the attached drawing, each of the tic-marks are equal and

represent 1 inch each. The angle B has measure 45. We can

see by the arc that the line AC, which equals 3 inches, is

not long enough to reach the slanted side of the 45 angle.

Therefore triangle ABC is not possible. We can also show

by the law of sines that no triangle ABC with the given

properties in possible.

5 0

3 years ago

A car drove 1550 miles on 45 gallons of gas. What is the Unit Rate of miles<br> per gallon of gas? *

Nataliya [291]

I’m not sure sorry!

7 0

3 years ago

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