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3 years ago

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A pyramid has a square base with side s. the hight of the pyramid is 2/3 that of its side. What expression for the volume of the

pyramid

1 answer:

Bess [88]3 years ago

6 0

i have no clue sorry i cant help you :)

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Consider these three numbers expressed in scientific notation: 8.2 × 10-3, 5.2 × 10-6, and 4.1 × 10-6. Which number is the great

Vedmedyk [2.9K]

1) 8.2 times 7
2)5.2 times 4
3)4.1 times 4
1) 57.4
2)20.8
3)16.4
Greatest:57.4
Least:16.4
Answer:57.4-16.4=41

6 0

3 years ago

sumaya is reading a book with 288 pages she has already read 90 pages she plans to read 20 more pages each day until she finshes

earnstyle [38]

Answer:

Step-by-step explanation:

you could create an equation which would be 288= 90 + 20(x)

x = the amount of days needed

answer would be 10 days

7 0

3 years ago

What is the next number in the sequence below?

zysi [14]

Answer is
B. 6
It’s dividing by 2

3 0

3 years ago

Read 2 more answers

The weight of a small Starbucks coffee is a normally distributed random variable with a mean of 330 grams and a standard deviati

just olya [345]

Answer:

Weights of at least 340.1 are in the highest 20%.

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.

In this problem, we have that:

$\mu = 330, \sigma = 12$

a. Highest 20 percent

At least X

100-20 = 80

So X is the 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.842.

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

$0.842 = \frac{X - 330}{12}$

$X - 330 = 12*0.842$

$X = 340.1$

Weights of at least 340.1 are in the highest 20%.

3 0

3 years ago

In early 2012, the Pew Internet and American Life Project asked a random sample of U.S. adults, "Do you ever ... use Twitter or

8090 [49]

Answer:

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And the confidence interval is given by:

(0.123, 0.177)

And for this case the interval contains the value 0.16, so then we can conclude at 5% of significance that the true proportion is not different from 0.16

Step-by-step explanation:

Previous concepts

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".

The population proportion have the following distribution

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

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And the confidence interval is given by:

(0.123, 0.177)

And for this case the interval contains the value 0.16, so then we can conclude at 5% of significance that the true proportion is not different from 0.16

3 0

3 years ago