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2 years ago

10

The scale of a model airplane is 1:72. If the wingspan on the model airplane is 7.5 inches, then the wingspan of the actual airp

lane is how many feet?

2 answers:

Leona [35]2 years ago

8 0

Answer:

45 feet

Step-by-step explanation:

svp [43]2 years ago

6 0

Answer:

45 feet

Step-by-step explanation:

Use ratios:

$\frac{1}{72}= \frac{7.5}{x}$

x = 540 inches

divide by 12 to get 45 feet

You might be interested in

Find each missing length to the nearest tenth.

Llana [10]

Answer:

8.944

Step-by-step explanation:

To find the missing Length, Use Pythagorean Theorem!

$a^2+b^2=c^2$

$4^2+8^2=c^2$

$16+64=c^2$

$80=c^2$

$\sqrt{80} =8.944$

so it is approximately 10 but not quiet

hope this helps

6 0

3 years ago

How do you spell 4 billion in scientific notation

Tema [17]

Answer:

<h2>4 bilion = 4 × 10⁹</h2>

Step-by-step explanation:

The scientific notation:

$a\cdot10^k$

where

$1\leq a$

4 billion:

in USA: 4,000,000,000

in Europe: 4 000 000 000 000

$4\underbrace{000000000}_9=4\cdot10^9$

3 0

2 years ago

Suppose the lifetime of a cell phone battery is normally distributed with a mean of 36 months and a standard deviation of 2 mont

solong [7]

Answer:

They should guarantee the lifetime of their batteries for 32 months.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of 36 months and a standard deviation of 2 months.

This means that $\mu = 36, \sigma = 2$

If the company wants to replace no more than 2% of all batteries, for how many months should they guarantee the lifetime of their batteries?

The guarantee should be the 2th percentile of lengths, which is X when Z has a pvalue of 0.02. So X when Z = -2.054.

$Z = \frac{X - \mu}{\sigma}$

$-2.054 = \frac{X - 36}{2}$

$X - 36 = -2.054*2$

$X = 31.89$

Rounding to the closest month, 32.

They should guarantee the lifetime of their batteries for 32 months.

3 0

2 years ago

A spool contains 270 inches of wire. How many pieces of wire, each with the a length of 1 7/8 inches, can be cut from the spool?

prisoha [69]

You would be able to cut 144 pieces of wire from the spool because 270/1 7/8 (or 1.875) equals 144

6 0

2 years ago

write the given equation into vertex form and sketch the graph. Determine the domain and range f(x)=3x^2-6+2 plss help

LuckyWell [14K]

Answer: the range would thus be [-3, 1/3].)

Step-by-step explanation:

1. To sketch the function f(x) = (2/3)x - 3, we first need to find two points that we can later join to sketch the line, for example the x- and y-intercepts.

a) The x-intercept occurs when f(x) = 0, so if f(x) = 0, then:

f(x) = (2/3)x - 3

0 = (2/3)x - 3

3 = (2/3)x (Add three to both sides)

3*(3/2) = x (Multiply both sides by 3/2)

9/2 = x

We have now found the x-intercept at (9/2, 0)

b) The y-intercept occurs when x = 0, so:

f(x) = (2/3)x - 3

f(0) = (2/3)*0 - 3

f(0) = -3

Now we know that the y-intercept is at (0, -3)

c) All that's left is to sketch the graph axes and label them, plot the two points, join them together using a ruler and label their coordinates.

2. The Domain is the range of x-values for which the function exists, and the Range is the range of y-values for which the function exists.

Since there haven't been any constraints specified, we can say that both the Domain and Range are (-∞, ∞), since the graph continues forever both along the x- and y-axis.

(Note that this isn't always the case and would change if, for example, the question stipulated that there was a domain of [0, 5] and you had to find the range. Then, you would calculate the value of y at each end of the domain (if x = 0, y = -3 and if x = 5, y = 1/3) - in my example, the range would thus be [-3, 1/3].)

4 0

3 years ago