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3 years ago

Fern rounded to the nearest ten to estimate 548-132. She subtracted 540-130 and got 410. Is Fern's estimate correct? Explain.

1 answer:

6 0

Fern's estimate is not correct because he rounded 548 wrong, it would be rounded to 550 instead since the number 8 is closer to 10. So the correct answer would be 420.

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Explain how you know these two figures are similar

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3 years ago

If the simple interest on $6000 for 9 years is $2160, then what is the interest rate?

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Step-by-step explanation:

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2 years ago

Of 580580 samples of seafood purchased from various kinds of food stores in different regions of a country and genetically compa

Lubov Fominskaja [6]

Answer:

a) The 99% confidence interval would be given (0.204;0.296).

b) We have 99% of confidence that the true population proportion of all seafood sold in the country that is mislabeled or misidentified is between (0.204;0.296).

c) No that's not true. Because the necessary assumptions and conditions for the confidence interval for the proportion are satisifed, so then we can use inferential statistics to interpret the interval to the population of interest.

Step-by-step explanation:

Part a

Data given and notation

n=580 represent the random sample taken

X represent the seafood sold in the country that is mislabeled or misidentified by the people

$\hat p=0.25$ estimated proportion of seafood sold in the country that is mislabeled or misidentified by the people

$\alpha=0.01$ represent the significance level (no given, but is assumed)

p= population proportion of seafood sold in the country that is mislabeled or misidentified by the people

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

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

The confidence interval would be given by this formula

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

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.25 - 2.58 \sqrt{\frac{0.25(1-0.25)}{580}}=0.204$

$0.25 + 2.58 \sqrt{\frac{0.25(1-0.25)}{580}}=0.296$

And the 99% confidence interval would be given (0.204;0.296).

Part b

We have 99% of confidence that the true population proportion of all seafood sold in the country that is mislabeled or misidentified is between (0.204;0.296).

Part c

A government spokesperson claimed that the sample size was too small, relative to the billions of pieces of seafood sold each year, to generalize. Is this criticism valid?

No that's not true. Because the necessary assumptions and conditions for the confidence interval for the proportion are satisifed, so then we can use inferential statistics to interpret the interval to the population of interest.

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4 years ago

Fiona, Peter and Angad share some sweets in the ratio 4:5:1. Fiona gets 40 sweets. How many sweets are there altogether?

steposvetlana [31]

Answer:

100

Step-by-step explanation:

sum the parts of the ratio, 4 + 5 + 1 = 10 parts

Fiona gets 40 sweets which is 4 parts of the ratio

Divide Fiona's share by 4 to find the value of one part of the ratio

40 ÷ 4 = 10 ← 1 part of the ratio

The total number of sweets is 10 parts , thus

number of sweets in total = 10 × 10 = 100

8 0

3 years ago

Read 2 more answers

Common household electric current is called alternating current because the current alternates direction within the wires. The v

Rainbow [258]

Answer:

n = 18 cycles

Step-by-step explanation:

To know how many times does the current oscillates in the given time, you take into account that the number of oscillation can be calculated by using the following expression:

$n=ft$ (1)

f: frequency of the oscillation of the current

t: time = 0.30s

The frequency is the number of cycles per second, that is, f = 60 cycles/s

You replace the values of f and t in the equation (1):

$n=(60\frac{cycles}{s})(0.30s)=18\ cycles$

In 0.30s the current oscillates 18 times

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3 years ago