Decrease £28 by 7%? im stuck on my homework

Mathematics

1 answer:

Murljashka [212]3 years ago

5 0

Answer:

£26.04

Step-by-step explanation:

The long way is to figure 7% of £28, then decrease that quantity by the amount you figured.

0.07 × £28 = £1.96

£28 - 1.96 = £26.04

I prefer to realize that the 100% of the value, decreased by 7%, will be 93% of the value. Then only one calculator operation is required.

0.93 × £28 = £26.04

_____

<em>Comment on percent</em>

Some folks get confused by percents. "Percent" essentially means "per hundred". The symbol % is a shorthand way to write /100, which means exactly the same thing. That is, 7% = 7/100 = 0.07. (Similarly, ‰ is a shorthand way to write /1000.)

<em>Comment on percentage increase or decrease</em>

When you're talking about a quantity decreased by some amount, as "£28 decreased by £7", you mean the value £7 is subtracted. When you say "decreased by 7%", the interpretation is different. We don't mean that £28 is decreased by 0.07 (to give £27.93); rather we mean £28 is decreased by 7% of £28. That is 7% of £28 is subtracted from £28.

You might be interested in

Help fast 55 points please hurry

SSSSS [86.1K]

Answer:

Step-by-step explanation:

There are 220 pages in carly's novel. At 4 hours, there is 80 pages left, but monica has 120

8 0

2 years ago

Read 2 more answers

The fracture strength of tempered glass averages 14 (measured in thousands of pounds per square inch) and has standard deviation

Wewaii [24]

Answer:

0.1587 = 15.87% probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2.

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 normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes 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 $s = \frac{\sigma}{\sqrt{n}}$ .