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3 years ago

I need help on 19 and 20

Mathematics

1 answer:

svp [43]3 years ago

8 0

Number 19 you are comparing one measurement to another. Since it says 1/2 inch equals 4 ft, we want to find out how many more inches are needed if the given scale was 2/3 = 4 ft. Now lets find a common denominator for both scales stated in inches. We have 2/3 inch and 1/2 inch. Our denominator are the bottom parts of the fraction where we need to find a common factor for the denominator so we can add or subtract fractions. We have a 3 and a 2. You may always use the multiplication between two denominators to find a common factor such as 3 times 2 which equals 6 for both denominators. Now we multiplied the 3 by 2 to get 6 so the top part (numerator needs to be multiplied the the 2 because we changed the bottom part by 2 as well. You should notice that when you reduce your fraction now 4/6 is 2/3. Just a self check example there. As for 1/2 we multiplied a 3 to get 6 for the denominator so we need to multiply the numerator by 3 as well. You now should have 4/6 and 3/6. Since the question asks for how many more inches we need to subtract 4/6 from 3/6 and we get 1/6 inch for our answer.

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Each leg of a 45-45-90 triangle has a length of 6 units. What is the length of its hypotenuse?

andreyandreev [35.5K]

Use the Pythagorean theorem:
$(\hbox{one leg})^2+(\hbox{the other leg})^2=(\hbox{hypotenuse})^2 \\
6^2+6^2=x^2 \\
6^2 \times 2=x^2 \\
\sqrt{6^2 \times 2}=x \\ \sqrt{6^2} \times \sqrt{2}=x \\ 6\sqrt{2}=x
$

The length of the hypotenuse is 6√2 units.

5 0

3 years ago

Consider a normal distribution curve where the middle 85 % of the area under the curve lies above the interval ( 8 , 14 ). Use t

NeTakaya

Answer:

$\mu = 11$

$\sigma = 2.08$

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

Middle 85%.

Values of X when Z has a pvalue of 0.5 - 0.85/2 = 0.075 to 0.5 + 0.85/2 = 0.925

Above the interval (8,14)

This means that when Z has a pvalue of 0.075, X = 8. So when $Z = -1.44, X = 8$ . So

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

$-1.44 = \frac{8 - \mu}{\sigma}$

$8 - \mu = -1.44\sigma$

$\mu = 8 + 1.44\sigma$

Also, when X = 14, Z has a pvalue of 0.925, so when $X = 8, Z = 1.44$

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

$1.44 = \frac{14 - \mu}{\sigma}$

$14 - \mu = 1.44\sigma$

$1.44\sigma = 14 - \mu$

Replacing in the first equation

$\mu = 8 + 1.44\sigma$

$\mu = 8 + 14 - \mu$

$2\mu = 22$

$\mu = \frac{22}{2}$

$\mu = 11$

Standard deviation:

$1.44\sigma = 14 - \mu$

$1.44\sigma = 14 - 11$

$\sigma = \frac{3}{1.44}$

$\sigma = 2.08$

7 0

2 years ago

Find the mean, median, mode, and range of this data: 49, 49, 54, 55, 52, 49, 55. If necessary, round to the nearest tenth.

Zigmanuir [339]

The mean is the average.
So, to find the mean you want o add up all of the numbers and then divide by the number of numbers.

49 + 49 + 54 + 55 + 52 + 49 + 575 = 363
363 / 7 = 51.85
Rounded to 52

For the median you want o line all of your number up from least to greatest and then find the middle number.

49,49,49,52,54,55,55

Your median is 52

The mode is the number that is listed most often

49 is listed 3 times
54 is listed 1 time
52 is listed 1 time
55 is listed 2 times

So, your mode is 49

4 0

3 years ago

Find the distance between (-7,-2) and (11,3)

jarptica [38.1K]

Answer:

The answer is