# Tara bought her dogs 2 boxes of dog biscuits for $3.99 each. She gave the cashier$20. How would you estimate how much change received?

Question
Fractions
Tara bought her dogs 2 boxes of dog biscuits for $3.99 each. She gave the cashier$20. How would you estimate how much change received?

2020-10-27
You can round up $3.99 to$4 so that the total cost is about 2×$4=$8. Since Tara gave $20, the change is the difference of what Tara gave and the total cost. So, the estimated change is:$20−$8=$12

### Relevant Questions

A random sample of $$\displaystyle{n}_{{1}}={16}$$ communities in western Kansas gave the following information for people under 25 years of age.
$$\displaystyle{X}_{{1}}:$$ Rate of hay fever per 1000 population for people under 25
$$\begin{array}{|c|c|} \hline 97 & 91 & 121 & 129 & 94 & 123 & 112 &93\\ \hline 125 & 95 & 125 & 117 & 97 & 122 & 127 & 88 \\ \hline \end{array}$$
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$$\displaystyle{X}_{{2}}:$$ Rate of hay fever per 1000 population for people over 50
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(a) What is the level of significance?
State the null and alternate hypotheses.
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$$\displaystyle{H}_{{0}}:\mu_{{1}}=\mu_{{2}},{H}_{{1}}:\mu_{{1}}>\mu_{{2}}$$
$$\displaystyle{H}_{{0}}:\mu_{{1}}=\mu_{{2}},{H}_{{1}}:\mu_{{1}}\ne\mu_{{2}}$$
$$\displaystyle{H}_{{0}}:\mu_{{1}}>\mu_{{2}},{H}_{{1}}:\mu_{{1}}=\mu_{{12}}$$
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The Student's t. We assume that both population distributions are approximately normal with unknown standard deviations,
The standard normal. We assume that both population distributions are approximately normal with unknown standard deviations,
The Student's t. We assume that both population distributions are approximately normal with known standard deviations,
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What is the value of the sample test statistic? (Test the difference $$\displaystyle\mu_{{1}}-\mu_{{2}}$$. Round your answer to three decimal places.)
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P-value $$\displaystyle>{0.250}$$
$$\displaystyle{0.125}<{P}-\text{value}<{0},{250}$$
$$\displaystyle{0},{050}<{P}-\text{value}<{0},{125}$$
$$\displaystyle{0},{025}<{P}-\text{value}<{0},{050}$$
$$\displaystyle{0},{005}<{P}-\text{value}<{0},{025}$$
P-value $$\displaystyle<{0.005}$$
Sketch the sampling distribution and show the area corresponding to the P-value.
P.vaiue Pevgiue
P-value f P-value
You may need to use the appropriate appendix table or technology to answer this question.
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State the null and alternate hypotheses.
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What are the degrees of freedom?
$$df_{N} = ?$$
$$df_{D} = ?$$
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