At the bank , mr smith changes a e5 note for 20p pieces . how many 20 pieces does he have

A manufacturer of paper coffee cups would like to estimate the proportion of cups that are defective (tears, broken seems, etc.)

Maksim231197 [3]

Answer:

a

The 95% confidence interval is $0.0503 < p < 0.1297$

b

The sample proportion is $\r p = 0.09$

c

The critical value is $Z_{\frac{\alpha }{2} } = 1.96$

d

The standard error is $SE =0.020$

Step-by-step explanation:

From the question we are told that

The sample size is n = 200

The number of defective is k = 18

The null hypothesis is $H_o : p = 0.08$

The alternative hypothesis is $H_a : p > 0.08$

Generally the sample proportion is mathematically evaluated as

$\r p = \frac{18}{200}$

$\r p = 0.09$

Given that the confidence level is 95% then the level of significance is mathematically evaluated as

$\alpha = 100 - 95$

$\alpha = 5\%$

$\alpha = 0.05$

Next we obtain the critical value of $\frac{ \alpha }{2}$ from the normal distribution table, the value is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the standard of error is mathematically represented as

$SE = \sqrt{\frac{\r p (1 - \r p)}{n} }$

substituting values

$SE = \sqrt{\frac{0.09 (1 - 0.09)}{200} }$

$SE =0.020$

The margin of error is

$E = Z_{\frac{ \alpha }{2} } * SE$

=> $E = 1.96 * 0.020$

=> $E = 0.0397$

The 95% confidence interval is mathematically represented as

$\r p - E < \mu < p < \r p + E$

=> $0.09 - 0.0397 < \mu < p < 0.09 + 0.0397$

=> $0.0503 < p < 0.1297$

7 0

2 years ago

Michael invests USD 20 000 at 9.6% p.a. compounded monthly.

alexandr1967 [171]

Given :

A = 25000

P = 20000

r % = 9.6 % = 0.096

n = 12

To Find :

The time taken say t.

Solution :

We know, compound interest is given by :

$A=P(1+\dfrac{r}{n})^{n.t}$

Taking log both sides :

$A=P(1+\dfrac{r}{n})^{n.t}\\\\log\ \dfrac{A}{P}= n.t\times log( 1+\dfrac{r}{n})\\\\t =\dfrac{1}{n}\times \dfrac{log\ \dfrac{A}{P}}{log(1+\dfrac{r}{n})}\\\\\\t=\dfrac{1}{12}\times \dfrac{log\ \dfrac{25000}{20000}}{log(1+\dfrac{0.096}{12})}\\\\\\t=2.33\ years$

Hence, this is the required solution.

5 0

2 years ago

The blood platelet counts of a group of women have a bell-shaped distribution with a mean of 247.9 and a standard deviation of

labwork [276]

Answer:

A) Approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3 = 95%

B) approximate percentage of women with platelet counts between 53.8 and 442.0 = 99.7%

Step-by-step explanation:

We are given;

mean;μ = 247.9

standard deviation;σ = 64.7

A) We want to find the approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3.

Now, from the image attached, we can see that from the empirical curve, the probability of 1 standard deviation from the mean is (34% + 34%) = 68 %.

While probability of 2 standard deviations from the mean is (13.5% + 34% + 34% + 13.5%) = 95%

Thus, approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3 = 95%

B) Now, we want to find the approximate percentage of women with platelet counts between 53.8 and 442.0.

53.8 and 442.0 represents 3 standard deviations from the mean.

Let's confirm that.

Since mean;μ = 247.9

standard deviation;σ = 64.7 ;

μ = 247.9

σ = 64.7

μ + 3σ = 247.9 + 3(64.7) = 442

Also;

μ - 3σ = 247.9 - 3(64.7) = 53.8

Again from the empirical curve attached, we cans that at 3 standard deviations from the mean, we have a percentage probability of;

(2.35% + 13.5% + 34% + 34% + 13.5% + 2.35%) = 99.7%

5 0

1 year ago

The horsepower , H(s), required for a racecar to overcome wind resistance is given by the function : H(s) = 0.003s^2+0.07s-0.027

mote1985 [20]

Average rate of change = [H(100) - H(80)] / (100 - 80)
H(100) = 0.003(100)^2 + 0.07(100) - 0.027 = 0.003(10000) + 0.07(100) - 0.027 = 30 + 7 - 0.027 = 36.973

H(80) = 0.003(80)^2 + 0.07(80) - 0.027 = 0.003(6400) + 0.07(80) - 0.027 = 19.2 + 5.6 - 0.027 = 24.773

Average rate of change = (36.973 - 24.773)/(100 - 80) = 12.2/20 = 0.61

Answer: B

8 0

2 years ago

Read 2 more answers

What is another way to group the factors (3x2)x5

tia_tia [17]

<u>Answer</u>

3×(2×5)

<u>Explanation</u>

Multiplication of numbers is associative. For example,

(a×b)×c = a×(b×c)

This is also called grouping. We multiply more than 2 numbers by grouping.

For the equation given above, (3x2)x5, it can also be grouped as 3×(2×5).