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3 years ago

If Jan can buy 12 copies of a certain book for $40, what is the unit rate for cost per copy? How much

Mathematics

1 answer:

natita [175]3 years ago

7 0

Answer:

12 copies=$40

1 copy=$40÷12=$3.33

18 copies=$3.33×18=$60

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Is every terminating decimal an integer?? Yes or no

sweet [91]

Integers do not have decimals...so ur answer is no. terminating decimals are not integers

7 0

3 years ago

PLEASE HELP ASAP!! I WILL GIVE U BRAINLIEST, PLZ SOLVE A person places a mirror between herself and a building. The mirror is 17

Semenov [28]

Answer:

11.6

Step-by-step explanation:

There are 2 traingles one from the person to bottom of mirror and one from the bottom of the mirror to the top of the building

these are conjugate triangles so if the 3m represents 17.5

what does the 2 m represent?

2*17.5/3=35/3=11 2/3 so 11.6

6 0

3 years ago

A prticular type of tennis racket comes in a midsize versionand an oversize version. sixty percent of all customers at acertain

svetlana [45]

Answer:

a) P(x≥6)=0.633

b) P(4≤x≤8)=0.8989 (one standard deviation from the mean).

c) P(x≤7)=0.8328

Step-by-step explanation:

a) We can model this a binomial experiment. The probability of success p is the proportion of customers that prefer the oversize version (p=0.60).

The number of trials is n=10, as they select 10 randomly customers.

We have to calculate the probability that at least 6 out of 10 prefer the oversize version.

This can be calculated using the binomial expression:

$P(x\geq6)=\sum_{k=6}^{10}P(k)=P(6)+P(7)+P(8)+P(9)+P(10)\\\\\\P(x=6) = \binom{10}{6} p^{6}q^{4}=210*0.0467*0.0256=0.2508\\\\P(x=7) = \binom{10}{7} p^{7}q^{3}=120*0.028*0.064=0.215\\\\P(x=8) = \binom{10}{8} p^{8}q^{2}=45*0.0168*0.16=0.1209\\\\P(x=9) = \binom{10}{9} p^{9}q^{1}=10*0.0101*0.4=0.0403\\\\P(x=10) = \binom{10}{10} p^{10}q^{0}=1*0.006*1=0.006\\\\\\P(x\geq6)=0.2508+0.215+0.1209+0.0403+0.006=0.633$

b) We first have to calculate the standard deviation from the mean of the binomial distribution. This is expressed as:

$\sigma=\sqrt{np(1-p)}=\sqrt{10*0.6*0.4}=\sqrt{2.4}=1.55$

The mean of this distribution is:

$\mu=np=10*0.6=6$

As this is a discrete distribution, we have to use integer values for the random variable. We will approximate both values for the bound of the interval.

$LL=\mu-\sigma=6-1.55=4.45\approx4\\\\UL=\mu+\sigma=6+1.55=7.55\approx8$

The probability of having between 4 and 8 customers choosing the oversize version is:

$P(4\leq x\leq 8)=\sum_{k=4}^8P(k)=P(4)+P(5)+P(6)+P(7)+P(8)\\\\\\P(x=4) = \binom{10}{4} p^{4}q^{6}=210*0.1296*0.0041=0.1115\\\\P(x=5) = \binom{10}{5} p^{5}q^{5}=252*0.0778*0.0102=0.2007\\\\P(x=6) = \binom{10}{6} p^{6}q^{4}=210*0.0467*0.0256=0.2508\\\\P(x=7) = \binom{10}{7} p^{7}q^{3}=120*0.028*0.064=0.215\\\\P(x=8) = \binom{10}{8} p^{8}q^{2}=45*0.0168*0.16=0.1209\\\\\\P(4\leq x\leq 8)=0.1115+0.2007+0.2508+0.215+0.1209=0.8989$

c. The probability that all of the next ten customers who want this racket can get the version they want from current stock means that at most 7 customers pick the oversize version.

Then, we have to calculate P(x≤7). We will, for simplicity, calculate this probability substracting P(x>7) from 1.

$P(x\leq7)=1-\sum_{k=8}^{10}P(k)=1-(P(8)+P(9)+P(10))\\\\\\P(x=8) = \binom{10}{8} p^{8}q^{2}=45*0.0168*0.16=0.1209\\\\P(x=9) = \binom{10}{9} p^{9}q^{1}=10*0.0101*0.4=0.0403\\\\P(x=10) = \binom{10}{10} p^{10}q^{0}=1*0.006*1=0.006\\\\\\P(x\leq 7)=1-(0.1209+0.0403+0.006)=1-0.1672=0.8328$

7 0

3 years ago

Which of these shows the result of using the first equation to substitute for y in the second equation, then combining like term

katen-ka-za [31]

Answer:

D. 8x=16

Step-by-step explanation:

If y=2x, then

2x+3y=16

2x+3(2x) =16

2x +6x=16

8x=16

5 0

3 years ago

Please answer, thank you and have a nice day

taurus [48]

Answer:

The inequality represented by the graph is y > $\frac{1}{3}$ x - 3

Step-by-step explanation:

The form of the linear equation is y = m x + b, where

m is the slope of the line

b is the y-intercept

The rule of the slope is m = $\frac{y2-y1}{x2-x1}$ , where

(x1, y1) and (x2, y2) are two points on the line

<em>To find the inequality represented by the graph, find at first the equation of the line</em>

∵ The line passes through points (0, -3) and (3, -2)

∴ x1 = 0 and y1 = -3

∴ x2 = 3 and y2 = -2

→ Substitute them in the rule of the slope above to find it

∵ m = $\frac{-2--3}{3-0}$ = $\frac{-2+3}{3}$ = $\frac{1}{3}$

∴ m = $\frac{1}{3}$

→ Substitute it in the form of the equation above

∴ y = $\frac{1}{3}$ x + b

∵ b is the y-intercept ⇒ value y at x = 0

∵ y = -3 at x = 0

∴ b = -3

→ Substitute it in the equation

∴ y = $\frac{1}{3}$ x + -3

∴ y = $\frac{1}{3}$ x - 3

→ Let us change it to inequality

∵ The line is dashed

∵ The shading area is above the line

∴ The sign of inequality should be >

∴ y > $\frac{1}{3}$ x - 3

∴ The inequality represented by the graph is y > $\frac{1}{3}$ x - 3

8 0

3 years ago