Please, help me I’m so dumb

Mathematics

1 answer:

Igoryamba3 years ago

7 0

Answer:

Step-by-step explanation:

You know that 9 = 10 - 1.

Then 9 of something is equal to 10 of it less one of it. Here, that "something" is four.

$\begin{array}{cl}9\times4&=10\text{ fours}-\boxed{1}\text{ four}\\&=\boxed{40}-4\\&=\boxed{36}\end{array}$

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<em>Comment on this math</em>

This illustrates a shortcut for multiplying by 9 that can be convenient for mental arithmetic. The idea is to multiply by 10, which just involves adding 0 (or moving the decimal point), then subtract the original number.

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LabTech is a company that manufactures microscopes and other laboratory instruments . On occasion, one of the microscopes is def

Scrat [10]

Answer:

0.0782 (7.82%)

Step-by-step explanation:

The required probability will be found by using the Binomial Distribution which fits the case of n independent events each with a probability of success equal to p with k successes.

The PMF (Probability Mass Function) is

$f(k,n,p)=\binom{n}{k}p^kq^{n-k}$

Where $q = 1-p$

LabTech states that the probability that a microscope is defective is 0.17%, p=0.0017, q=0.9983. We need to know the probability that k=1 microscope is defective out of a set of n=50 of them. We now apply the formula

$f(1,50,0.0017)=\binom{50}{1}0.0017^10.9983^{49}=0,0782$