All categories

3 years ago

An element with mass 630 grams decays by 18.8% per minute. How much of the

Mathematics

1 answer:

LenaWriter [7]3 years ago

7 0

Answer:

-199.1

Step-by-step explanation:

18.8% × 7= 131.6%

630×131.6=82908 move the decimal two places to the left you get 829.08

630-829.08= -199.08 round to the nearest tenth you get -199.1

You might be interested in

Find the product or quotient. Express using positive exponents

Alex73 [517]

Answer:

Step-by-step explanation:

$x^{-6}*x^{-5}=x^{(-6)+(-5)}=x^{-11}=\frac{1}{x^{11}}$

$x^{a}*x^{b}=x^{a+b}\\\\x^{-a}=\frac{1}{x^{a}}$

6 0

4 years ago

Joan has a credit card that uses the previous balance method. The opening balance of one of her 30-day billing cycles was $6390,

Gekata [30.6K]

It would be something that looks like this:

((6390 * 0.17)/365) x 3

3 0

4 years ago

Read 2 more answers

Many high school students take the AP tests in different subject areas. In 2007, of the 144,796 students who took the biology ex

Nataly [62]

Answer:

$(0.582-0.485) - 1.64 \sqrt{\frac{0.582(1-0.582)}{144796} +\frac{0.485(1-0.485)}{211693}}=0.0942$

$(0.582-0.485) + 1.64 \sqrt{\frac{0.582(1-0.582)}{144796} +\frac{0.485(1-0.485)}{211693}}=0.09978$

And the 90% confidence interval would be given (0.0942;0.09978).

We are confident at 90% that the difference between the two proportions is between $0.0942 \leq p_A -p_B \leq 0.09978$

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".

$p_A$ represent the real population proportion female for Biology

$\hat p_A =\frac{84199}{144796}=0.582$ represent the estimated proportion female for biology

$n_A=144796$ is the sample size for A

$p_B$ represent the real population proportion female for calculus AB

$\hat p_B =\frac{102598}{211693}=0.485$ represent the estimated proportion female for Calculus AB

$n_B=211693$ is the sample size required for B

$z$ 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.