What is (9−7)×9−9+3? Use order of operations to evaluate the expression below.

A cup of coffee at 85 degrees Celsius is placed in a room at 25 degrees Celsius. Suppose that the coffee cools at a rate of 5 de

bezimeni [28]

Answer: k = - 6.6667

Step-by-step explanation:

this is quite very simple to begin. I would encourage you take other practice questions similar to help with understanding it.

let us begin.

Given that ;

dT/dt = k ( Tm - T) where Tm is the temp of the medium

dT/dt = 5 degrees Celsius per minute when T = 70

so we have that, 5 = k ( 25 - 70)

remember to convert 5 degree celsius per minute to seconds

we have that;

5*60(sec) = k ( 25 - 70)

k = 5*60 / ( 25 - 70)

k = - 6.6667

note K is negative because we consider it for cooling process (temp decreasing).

cheers i hope this helps!!!

3 0

3 years ago

This will be so helpful right now thank

RoseWind [281]

Answer:

55 ft.

Step-by-step explanation:

First find the area of Lot X

67 • 70 = 4,690

Subtract the are of Lot X from the total area

8,375 - 4,690 = 3,685

3,685 is the area of Lot Y

Now divide 3,685 by the length of Lot Y : 67

3,685 ÷ 67 = 55

The width of Lot Y is 55 ft.

Hope this helps!

5 0

3 years ago

WILL MARK BRAINLIEST TO THE BEST ANSWER!!

ruslelena [56]

$\dfrac{12^3}{12^7} = 12^{3 - 7} = 12^{-4} = \dfrac{1}{12^4}$

Answer: B

8 0

3 years ago

Read 2 more answers

Suppose that 20% of the residents in a certain state support an increase in the property tax. An opinion poll will randomly samp

aleksklad [387]

Answer:

95.44% probability the resulting sample proportion is within .04 of the true proportion.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For the sampling distribution of the sample proportion in sample of size n, the mean is $\mu = p$ and the standard deviation is $s = \sqrt{\frac{p(1-p)}{n}}$