WILL MARK BRAINLIEST What is the surface area of the prism?

Carpet for one office costs $210. If the carpet sells for $8.75 per

Answer:

a.

Let x be the number of square yards of carpeting for which the total cost charged by the two companies will be the same.

We have an expression for the total cost of Country Carpets:

($22/ 1 yd^2)* (x yd^2) + $100

= $22*x+ $100

or 22x+ 100

We also have another expression for the total cost of City Carpets:

($25/ 1 yd^2)* (x yd^2)+ $70

= $25*x+ $70

or 25x+ 70

Now set the two expressions to be equal:

22x+ 100= 25x+ 70

⇒ 100- 70= 25x -22x

⇒ 30= 3x

⇒ 30/3= x

⇒ 10= x

The final answer for a is 10 square yards of carpeting~

b.

Let's assume that Mr. Shu wants to install carpeting for 1 square yard.

Country Carpets: $22*1+ $100= $122

City Carpets: $25*1+ $70= $95

Therefore, Mr. Shu will be likely to choose City Carpets if he wants to install carpeting for 1 square yard.

Now let's try x=11 (square yard):

Country Carpets= $22*11+ $100= $342

City Carpets= $25*11+ $70= $345

Therefore, Mr. Shu will be likely to choose Country Carpets if he wants to install carpeting for 11 square yard.

If you paid really close attention, you would notice that the price of City Carpets will be cheaper than the other when x is >0 and <10. At x=10, the price is equal. When x is >10, the price of Country Carpets will be cheaper than the other one.

So it depends:

If x were >0 and <10, Mr. Shu would be likely to choose City Carpets.

If x were 10, Mr. Shu could choose either Country Carpets or City Carpets.

If x were > 10, Mr. Shu would be likely to choose Country Carpets.

Hope this helps~

Step-by-step explanation:

7 0

2 years ago

Suppose a geyser has a mean time between eruptions of 72 minutes. Let the interval of time between the eruptions be normally dis

nikitadnepr [17]

Answer:

(a) The probability that a randomly selected time interval between eruptions is longer than 82 minutes is 0.3336.

(b) The probability that a random sample of 13-time intervals between eruptions has a mean longer than 82 minutes is 0.0582.

(c) The probability that a random sample of 34 time intervals between eruptions has a mean longer than 82 minutes is 0.0055.

(d) Due to an increase in the sample size, the probability that the sample mean of the time between eruptions is greater than 82 minutes decreases because the variability in the sample mean decreases as the sample size increases.

(e) The population mean must be more than 72, since the probability is so low.

Step-by-step explanation:

We are given that a geyser has a mean time between eruptions of 72 minutes.

Also, the interval of time between the eruptions be normally distributed with a standard deviation of 23 minutes.

(a) Let X = the interval of time between the eruptions

So, X ~ N( $\mu=72, \sigma^{2} =23^{2}$ )

The z-score probability distribution for the normal distribution is given by;

Z = $\frac{X-\mu}{\sigma}$ ~ N(0,1)

where, $\mu$ = population mean time = 72 minutes

$\sigma$ = standard deviation = 23 minutes

Now, the probability that a randomly selected time interval between eruptions is longer than 82 minutes is given by = P(X > 82 min)

P(X > 82 min) = P( $\frac{X-\mu}{\sigma}$ > $\frac{82-72}{23}$ ) = P(Z > 0.43) = 1 - P(Z $\leq$ 0.43)

= 1 - 0.6664 = 0.3336

The above probability is calculated by looking at the value of x = 0.43 in the z table which has an area of 0.6664.

(b) Let $\bar X$ = sample mean time between the eruptions

The z-score probability distribution for the sample mean is given by;

Z = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = population mean time = 72 minutes

$\sigma$ = standard deviation = 23 minutes

n = sample of time intervals = 13

Now, the probability that a random sample of 13 time intervals between eruptions has a mean longer than 82 minutes is given by = P( $\bar X$ > 82 min)

P( $\bar X$ > 82 min) = P( $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ > $\frac{82-72}{\frac{23}{\sqrt{13} } }$ ) = P(Z > 1.57) = 1 - P(Z $\leq$ 1.57)

= 1 - 0.9418 = 0.0582

The above probability is calculated by looking at the value of x = 1.57 in the z table which has an area of 0.9418.

(c) Let $\bar X$ = sample mean time between the eruptions

The z-score probability distribution for the sample mean is given by;

Z = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = population mean time = 72 minutes

$\sigma$ = standard deviation = 23 minutes

n = sample of time intervals = 34

Now, the probability that a random sample of 34 time intervals between eruptions has a mean longer than 82 minutes is given by = P( $\bar X$ > 82 min)

P( $\bar X$ > 82 min) = P( $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ > $\frac{82-72}{\frac{23}{\sqrt{34} } }$ ) = P(Z > 2.54) = 1 - P(Z $\leq$ 2.54)

= 1 - 0.9945 = 0.0055

The above probability is calculated by looking at the value of x = 2.54 in the z table which has an area of 0.9945.

(d) Due to an increase in the sample size, the probability that the sample mean of the time between eruptions is greater than 82 minutes decreases because the variability in the sample mean decreases as the sample size increases.

(e) If a random sample of 34-time intervals between eruptions has a mean longer than 82 minutes, then we conclude that the population mean must be more than 72, since the probability is so low.

6 0

3 years ago

At the beginning of the month Riley’s balance was $128. What was her balance at the end of the month after all of her deposits a

patriot [66]

Answer:

In order for me to answer this I need to know how much she had left.

Step-by-step explanation:

I can edit my answer once you tell me

8 0

2 years ago

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Daisy wants to make 12 clay animals to give away as Valentines gifts. Each animal she makes uses 1/2 of a stick of clay. How muc