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3 years ago

8

find the surface area of a right square pyramid if the area of the base is 144 cm squared and the height of the pyramid is 42 cm

.

1 answer:

xxTIMURxx [149]3 years ago

4 0

Area of a pyramid is ⅓ * area of Base * height

or ⅓ * 144 * 42 or 2016 cm³

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Eight times a sum of a number is 5

nata0808 [166]

Answer:

Step-by-step explanation:

So 8 times what is 5?

8 times x=5

x=0.625

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2 years ago

The sugar content of the syrup in canned peaches is normally distributed. A random sample of n = 10 cans yields a sample standar

Serggg [28]

Answer:

The 95% confidence interval is given by:

3.30<σ<8.76

Step-by-step explanation:

1) Data given and notation

s=4.798 represent the sample standard deviation

$\bar x$ represent the sample mean

n=10 the sample size

Confidence=95% or 0.95

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 mean or variance 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.

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=10-1=9$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical values.

The excel commands would be: "=CHISQ.INV(0.025,9)" "=CHISQ.INV(0.975,9)". so for this case the critical values are:

$\chi^2_{\alpha/2}=19.022$

$\chi^2_{1- \alpha/2}=2.700$

And replacing into the formula for the interval we got:

$\frac{(9)(4.798)^2}{19.022} \leq \sigma \frac{(9)(4.798)^2}{2.700}$

$10.892 \leq \sigma^2 \leq 76.736$

Now we just take square root on both sides of the interval and we got:

$3.30 \leq \sigma \leq 8.76$

So the best option would be:

3.30<σ<8.76

7 0

3 years ago

-9 · (-8) =<br> O 72<br> 00<br> o<br> 00<br> O-72

Masja [62]

Answer:

72

Step-by-step explanation:

Hope it helps

6 0

3 years ago

Which of the following statements are true of literal equations?

Elden [556K]

Answer:

1. They consist primarily of variables.

2. They are often called formulas.

4. They often describe real-world relationships.

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3 years ago

Alex buys 2 1/2 pounds of grapes. He buys 1 1/4 times as many pounds of apples as grapes. How many pounds of apples does he buy?

galina1969 [7]

Given:
grapes = 2 1/2 pounds
apples = 1 1/4 times as many pounds as grapes.

For easier computation, let us convert these fractions into numbers with decimal places.

2 1/2 pounds = 2.50 pounds
1 1/4 times = 1.25

Apples = 2.50 pounds * 1.25 = 3.125 pounds of apples.

Or we still use fractions. We need to convert the mixed fractions into improper fractions.

2 1/2 = 5/2
1 1/4 = 5/4

5/2 * 5/4 = 5*5 / 2*4 = 25/8 is simplified to 3 1/8 pounds

3 0

3 years ago