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4 years ago

7

I have 4 pencils, 3 ball-point pens, and a felt-tip marker in a cup on my desk. i choose a writing implement from the cup random

ly. what is the probability that it is not a ball-point pen?

1 answer:

Sonbull [250]4 years ago

5 0

The probability would be 5/8 chances.

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6.945 seconds was the difference between Nancy's and Betty's swim times.

27.949 - 21.004 = 6.945

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3 years ago

Please help me this is for a test. Thank you so much whoever answers this.

Alenkinab [10]

Answer: Pretty sure the answer is 3.

Step-by-step explanation:

$\frac{2(4+7)-7}{5}$

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$\frac{22-7}{5}$

$\frac{15}{5}$

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3 years ago

Can someone please help me as soon as possible thanks

exis [7]

Left row 1. Supplementary 2.complementary 3 supplementary
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3 years ago

How can I make this true 3×26+4 = 90

kap26 [50]

You could do 78+4 because 26x3 is 78 and then add the 12 and it will be 90

4 0

3 years ago

Read 2 more answers

(CO 3) Fifty-four percent of US teens have heard of a fax machine. You randomly select 12 US teens. Find the probability that th

11111nata11111 [884]

Answer:

a) $P(X=6)=(12C6)(0.54)^6 (1-0.54)^{12-6}=0.217$

b) $P(X> 8) = P(X\geq 9)= P(X=9)+P(X=10)+P(X=11)+P(X=12)$

$P(X=9)=(12C9)(0.54)^9 (1-0.54)^{12-9}=0.0836$

$P(X=10)=(12C10)(0.54)^{10} (1-0.54)^{12-10}=0.0294$

$P(X=11)=(12C11)(0.54)^{11} (1-0.54)^{12-11}=0.00628$

$P(X=12)=(12C12)(0.54)^{12} (1-0.54)^{12-12}=0.000615$

And adding the values we got:

$P(X> 8) = P(X\geq 9)= P(X=9)+P(X=10)+P(X=11)+P(X=12)= 0.0836+0.0294+0.00628+0.000615 = 0.120$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest "number of teens that have heard of a fax machine", on this case we now that:

$X \sim Binom(n=12, p=0.54)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Part a

For this case we want this probability:

$P(X=6)=(12C6)(0.54)^6 (1-0.54)^{12-6}=0.217$

Part b

For this case we want this probability:

$P(X> 8) = P(X\geq 9)= P(X=9)+P(X=10)+P(X=11)+P(X=12)$

$P(X=9)=(12C9)(0.54)^9 (1-0.54)^{12-9}=0.0836$

$P(X=10)=(12C10)(0.54)^{10} (1-0.54)^{12-10}=0.0294$

$P(X=11)=(12C11)(0.54)^{11} (1-0.54)^{12-11}=0.00628$

$P(X=12)=(12C12)(0.54)^{12} (1-0.54)^{12-12}=0.000615$

And adding the values we got:

$P(X> 8) = P(X\geq 9)= P(X=9)+P(X=10)+P(X=11)+P(X=12)= 0.0836+0.0294+0.00628+0.000615 = 0.120$

5 0

4 years ago

Read 2 more answers