Need help with homework plz, also will give brainiest to who ever gets the question right first!

Suppose y varies directly with x. Write a direct variation equation that relates x and y. Then find the value of y when x=8.

anastassius [24]

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5 0

3 years ago

If 50 percent of x=66 then x =

sasho [114]

Answer:

132

Step-by-step explanation:

50 % means half

so 66 is half of whatever x is.

to find x you have to multiply 66 by 2 or add 66 to 66 which will give you 132 either way.

<em>Hope this helps you! have an amazing day :)</em>

7 0

3 years ago

Read 2 more answers

A recent Gallup poll found that 36% of U.S. teens aged from 13 to 17 years old have a computer with [(6)] Internet access in the

In-s [12.5K]

Answer:

Step-by-step explanation:

a) The population parameter is the population proportion.

b) Confidence interval is written as

Sample proportion ± margin of error

Margin of error = z × √pq/n

Where

z represents the z score corresponding to the confidence level

p = sample proportion. It also means probability of success

q = probability of failure

q = 1 - p

p = x/n

Where

n represents the number of samples

x represents the number of success

From the information given,

n = 1028

p = 36/100 = 0.36

q = 1 - 0.36 = 0.64

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.99 = 0.1

α/2 = 0.01/2 = 0.005

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.05 = 0.995

The z score corresponding to the area on the z table is 2.58. Thus, confidence level of 99% is 2.58

Therefore, the 99% confidence interval is

0.36 ± 2.58 × √(0.36)(0.64)/1028

The lower limit of the confidence interval is

0.36 - 0.039 = 0.321

The upper limit of the confidence interval is

0.36 + 0.039 = 0.399

Therefore, with 99% confidence interval, the proportion of U.S. teens aged from 13 to 17 years old that have a computer with Internet access in their rooms is between 0.321 and 0.399

c) for a margin of error of 1%, that is 1/100 = 0.01, then

0.01 = 2.58 × √(0.36)(0.64)/n

0.01/2.58 = √0.2304/n

0.00387596899 = √0.2304/n

Square both sides

0.00001502314 = 0.2304/n

n = 0.2304/0.00001502314

n = 15336

5 0

4 years ago

Please help this question.

sergejj [24]

Answer:

a). 59.049°C

b). 2.1179 seconds

Step-by-step explanation:

Expression representing the final temperature after decrease in temperature of the metal from 100°C to T°C is,

T = $100(0.9)^{x}$

where x = duration of cooling

a). Temperature when x = 5 seconds

T = 100(0.9)⁵

= 59.049

≈ 59.049°C

b). If the temperature of the metal decreases from 100°C to 80°C

Which means for T = 80°C we have to calculate the duration of cooling 'x' seconds

80 = $100(0.9)^{x}$

0.8 = $(0.9)^{x}$

By taking log on both the sides

log(0.8) =log[ $(0.9)^{x}$ ]

-0.09691 = x[log(0.9)]

-0.09691 = -0.045757x

x = $\frac{0.09691}{0.045757}$

x = 2.1179

x ≈ 2.1179 seconds

3 0

3 years ago

How many meters is the foot of the ladder from the wall? Round your final answer to the nearest tenth.

Alex Ar [27]

Answer:

Step-by-step explanation:

6

5 0

3 years ago