The quotient of a number and 4 decreased by 10 is 2

nventing is a difficult way to make money. Only 5% of new patents earn a substantial profit. A certain city has just had30 indep

Arlecino [84]

Answer:

$P(X \geq 2) = 1-P(X$

And we can find the individual probabilities using the probability mass function and we got:

$P(X=0) = (30C0) (0.05)^0 (1-0.05)^{30-0} =0.2146$

$P(X=1) = (30C1) (0.05)^1 (1-0.05)^{30-1} = 0.3389$

And replacing we got:

$P(X \geq 2) = 1-P(X$

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".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=30, p=0.05)$

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:

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

Solution to the problem

For this case we want this probability:

$P(X \geq 2)$

And we can use the complement rule and we got:

$P(X \geq 2) = 1-P(X$

And we can find the individual probabilities using the probability mass function and we got:

$P(X=0) = (30C0) (0.05)^0 (1-0.05)^{30-0} =0.2146$

$P(X=1) = (30C1) (0.05)^1 (1-0.05)^{30-1} = 0.3389$

And replacing we got:

$P(X \geq 2) = 1-P(X$

3 0

3 years ago

J.J.Bean sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet.

melamori03 [73]

Answer:

99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].

Step-by-step explanation:

We are given that a random sample of 16 sales receipts for mail-order sales results in a mean sale amount of $74.50 with a standard deviation of $17.25.

A random sample of 9 sales receipts for internet sales results in a mean sale amount of $84.40 with a standard deviation of $21.25.

The pivotal quantity that will be used for constructing 99% confidence interval for true mean difference is given by;

P.Q. = $\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ~ $t__n_1_+_n_2_-_2$

where, $\bar X_1$ = sample mean for mail-order sales = $74.50

$\bar X_2$ = sample mean for internet sales = $84.40

$s_1$ = sample standard deviation for mail-order purchases = $17.25

$s_2$ = sample standard deviation for internet purchases = $21.25

$n_1$ = sample of sales receipts for mail-order purchases = 16

$n_2$ = sample of sales receipts for internet purchases = 9

Also, $s_p =\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }$ = $\sqrt{\frac{(16-1)\times 17.25^{2}+(9-1)\times 21.25^{2} }{16+9-2} }$ = 18.74

The true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is represented by ( $\mu_1-\mu_2$ ).

Now, 99% confidence interval for ( $\mu_1-\mu_2$ ) is given by;

= $(\bar X_1-\bar X_2) \pm t_(_\frac{\alpha}{2}_) \times s_p \times \sqrt{\frac{1}{n_1} +\frac{1}{n_2}}$

Here, the critical value of t at 0.5% level of significance and 23 degrees of freedom is given as 2.807.

= $(74.50-84.40) \pm (2.807 \times 18.74 \times \sqrt{\frac{1}{16} +\frac{1}{9}})$

= [$-31.82 , $12.02]

Hence, 99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].

5 0

3 years ago

Concesion tables contain ratios that can be used to convert units of length, weight, or capacity. You must multiply the

Aleonysh [2.5K]

Answer:

Step-by-step explanation:

yard; the ratio of feet to yards is

7 0

3 years ago

Andy and Christopher are measuring a liquid solution using graduated cylinders, Andy uses 3.5 liters of the liquid solution, and

Gre4nikov [31]

Answer:

$Ratio = 0.74$

Step-by-step explanation:

Represent

- Andy with A

- Christopher with C

$A = 3.5L$

$C = 2580mL$

Required

Determine the ratio of C to A

Ratio is represented as thus:

$Ratio = C:A$

Rewrite as fraction

$Ratio = \frac{C}{A}$

This gives

$Ratio = \frac{2580mL}{3.5L}$

Convert L to mL

$Ratio = \frac{2580mL}{3.5*1000mL}$

$Ratio = \frac{2580mL}{3500mL}$

$Ratio = \frac{2580}{3500}$

$Ratio = 0.73714285714$

$Ratio = 0.74$ --- Approximated

6 0

3 years ago

Please explain the answer to 4367 ÷ 0.004

boyakko [2]

4367 ÷ 0.004 is 1091750. To solve this, you can use long division, by setting up the equation. Make sure to move the decimal. Then, divide the first digit, then the first two digits, and so on.

7 0

4 years ago