Ask question

Ask question

All categories

3 years ago

7

X is a number. It is divided by 3, and 5 is subtracted from result is then multiplied by 7. lf the final answer is 28 what numbe

r is X

1 answer:

Taya2010 [7]3 years ago

6 0

7(1/3x- 5) = 28
7/3x - 35 = 28
7/3x = 28 + 35
7/3x = 63
x = 63 * 3/7
x = 189/7 = 27 <==

You might be interested in

13. f(x) = -x + 4x^3 -2

Oksi-84 [34.3K]

Answer:

x = 5

Step-by-step explanation:

7 0

3 years ago

What is three tenths times two and five sixths?

Virty [35]

To multiply fraction do top x top and bottom x bottom
so convert $2 \frac{5}{6}$ into $\frac{17}{6}$
then do $\frac{3}{10} * \frac{17}{6} = \frac{3*17}{10*6} = \frac{51}{60} = \frac{17}{20}$

3 0

3 years ago

Read 2 more answers

Please help its due tommorrow morning!

LenaWriter [7]

Answer: $324

Step-by-step explanation:

i=prt

i=(6000)(.054)(1)

i=324

4 0

3 years ago

Read 2 more answers

Two interior angles of a triangle each measure 34°. What is the measure of the third interior angle?

lana [24]

Answer:

D. 112

Step-by-step explanation:

Since we know that a triangle totals 180 degrees, we can easily figure out the third angle. Since each measure 34 degrees, simply multiply by 2. You get 68 degrees. Then you do 180-68 to get 112.

4 0

3 years ago

In March 2015, the Public Policy Institute of California (PPIC) surveyed 7525 likely voters living in California. This is the 14

lbvjy [14]

Answer:

We are confident at 99% that the difference between the two proportions is between $0.380 \leq p_{Republicans} -p_{Democrats} \leq 0.420$

Step-by-step explanation:

Part a

Data given and notation

$X_{D}=3266$ represent the number people registered as Democrats

$X_{R}=2137$ represent the number of people registered as Republicans

$n=7525$ sampleselcted

$\hat p_{D}=\frac{3266}{7525}=0.434$ represent the proportion of people registered as Democrats

$\hat p_{R}=\frac{2137}{7525}=0.284$ represent the proportion of people registered as Republicans

The standard error is given by this formula:

$SE=\sqrt{\frac{\hat p_D (1-\hat p_D)}{n_{D}}+\frac{\hat p_R (1-\hat p_R)}{n_{R}}}$

And the standard error estimated given by the problem is 0.008

Part b

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$p_A$ represent the real population proportion of Democrats that approve of the way the California Legislature is handling its job

$\hat p_A =\frac{1894}{3266}=0.580$ represent the estimated proportion of Democrats that approve of the way the California Legislature is handling its job

$n_A=3266$ is the sample size for Democrats

$p_B$ represent the real population proportion of Republicans that approve of the way the California Legislature is handling its job

$\hat p_B =\frac{385}{2137}=0.180$ represent the estimated proportion of Republicans that approve of the way the California Legislature is handling its job

$n_B=2137$ is the sample for Republicans

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

The confidence interval for the difference of two proportions would be given by this formula

$(\hat p_A -\hat p_B) \pm z_{\alpha/2} \sqrt{\frac{\hat p_A(1-\hat p_A)}{n_A} +\frac{\hat p_B (1-\hat p_B)}{n_B}}$

For the 90% confidence interval the value of $\alpha=1-0.90=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.64$

And replacing into the confidence interval formula we got:

$(0.580-0.180) - 1.64 \sqrt{\frac{0.580(1-0.580)}{3266} +\frac{0.180(1-0.180)}{2137}}=0.380$

$(0.580-0.180) + 1.64 \sqrt{\frac{0.580(1-0.580)}{3266} +\frac{0.180(1-0.180)}{2137}}=0.420$

And the 99% confidence interval would be given (0.380;0.420).

We are confident at 99% that the difference between the two proportions is between $0.380 \leq p_{Republicans} -p_{Democrats} \leq 0.420$

5 0

3 years ago