Given the following hypotheses: H0: μ = 490 H1: μ ≠ 490 A random sample of 15 observations is selected from a normal population. The sample mean was 495 and the sample standard deviation 9. Using the 0.01 significance level:
a.) State the decision rule.
b.) Compute the value of the test statistic.
c.) What is your decision regarding the null hypothesis?

Answer:

The​ z-score for 1880 is 1.34.

The​ z-score for 1190 is -0.88.

The​ z-score for 2130 is 2.15.

The​ z-score for 1350 is -0.37.

And the z-score of 2130 is considered to be unusual.

Step-by-step explanation:

The complete question is: A standardized​ exam's scores are normally distributed. In recent​ years, the mean test score was 1464 and the standard deviation was 310. The test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350. Find the​ z-scores that correspond to each value and determine whether any of the values are unusual. The​ z-score for 1880 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1190 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 2130 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1350 is nothing. ​(Round to two decimal places as​ needed.) Which​ values, if​ any, are​ unusual? Select the correct choice below​ and, if​ necessary, fill in the answer box within your choice. A. The unusual​ value(s) is/are nothing. ​(Use a comma to separate answers as​ needed.) B. None of the values are unusual.

We are given that the mean test score was 1464 and the standard deviation was 310.

Let X = standardized​ exam's scores

The z-score probability distribution for the normal distribution is given by;

                          Z  =  [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = mean test score = 1464

           [tex]\sigma[/tex] = standard deviation = 310

S, X ~ Normal([tex]\mu=1464, \sigma^{2} = 310^{2}[/tex])

Now, the test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350.

So, the z-score of 1880 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                      =  [tex]\frac{1880-1464}{310}[/tex]  = 1.34

The z-score of 1190 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1190-1464}{310}[/tex]  = -0.88

The z-score of 2130 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{2130-1464}{310}[/tex]  = 2.15

The z-score of 1350 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1350-1464}{310}[/tex]  = -0.37

Now, the values whose z-score is less than -1.96 or higher than 1.96 are considered to be unusual.

According to our z-scores, only the z-score of 2130 is considered to be unusual as all other z-scores lie within the range of -1.96 and 1.96.

Answer:

[tex] d = 7 + 3\sqrt{3} [/tex] and

[tex] d = 7 - 3\sqrt{3} [/tex]

Step-by-step explanation:

To solve the equation, [tex] d^2 - 14d - 22 = 0 [/tex], using the quadratic formula,

Recall: quadratic formula = [tex] \frac{-b ± \sqrt{b^2 - 4ac}}{2a} [/tex]

Where,

a = 1

b = -14

c = 22

Plug in your values into the formula and solve:

[tex] \frac{-(-14) ± \sqrt{(-14)^2 - 4(1)(22)}}{2(1)} [/tex]

[tex] \frac{14 ± \sqrt{196 - 88}}{2} [/tex]

[tex] \frac{14 ± \sqrt{108}}{2} [/tex]

[tex] d = \frac{14 + \sqrt{108}}{2} [/tex]

[tex] d = \frac{14 + 6\sqrt{3}}{2} [/tex]

[tex] d = (\frac{2(7 + 3\sqrt{3})}{2} [/tex]

[tex] d = 7 + 3\sqrt{3} [/tex]

And

[tex] d = \frac{14 - \sqrt{108}}{2} [/tex]

[tex] d = \frac{14 - 6\sqrt{3}}{2} [/tex]

[tex] d = (\frac{2(7 - 3\sqrt{3})}{2} [/tex]

[tex] d = 7 - 3\sqrt{3} [/tex]

Answer:

[tex]a = \frac{3}{4}[/tex]

Step-by-step explanation:

Let's convert everything to sixths to make it easier to work with.

[tex]\frac{4}{6}a - \frac{1}{6} = \frac{2}{6}[/tex]

Add 1/6 to both sides:

[tex]\frac{4}{6}a = \frac{3}{6}[/tex].

Dividing both sides by 4/6:

[tex]a = \frac{3}{6} \div \frac{4}{6}\\\\a = \frac{3}{6} \cdot \frac{6}{4}\\\\a = \frac{18}{24}\\\\a = \frac{3}{4}[/tex]

Hope this helped!

Answer:

Step-by-step explanation:

Given that v(x) = g(x)×(3/2*x^4+4x-1)

Let's find V'(2)

V(x) is a product of two functions

● V'(x) = g'(x)×(3/2*x^4+4x-1)+ g(x) ×(3/2*x^4+4x-1)

We are interested in V'(2) so we will replace x by 2 in the expression above.

g'(2) can be deduced from the graph.

● g'(2) is equal to the slope of the tangent line in 2.

● let m be that slope .

● g'(2) = m =>g'(2) = rise /run

● g'(2) = 2/1 =2

We've run 1 square to the right and rised 2 squares up to reach g(2)

g(2) is -1 as shown in the graph.

■■■■■■■■■■■■■■■■■■■■■■■■■■

Let's derivate the second function.

Let h(x) be that function

● h(x) = 3/2*x^4 +4x-1

● h'(x) = 3/2*4*x^3 + 4

● h'(x) = 6x^3 +4

Let's calculate h'(2)

● h'(2) = 6 × 2^3 + 4

● h'(2) = 52

Let's calculate h(2)

●h(2) = 3/2*2^4 + 4×2 -1

●h(2)= 31

■■■■■■■■■■■■■■■■■■■■■■■■■■

Replace now everything with its value to find V'(2)

● V'(2) = g'(2)×h(2) + g(2)× h'(2)

● V'(2)= 2×31 + (-1)×52

●V'(2) = 61 -52

●V'(2)= 9

Answer:

Deposit value(P) = $17,760 (Approx)

Step-by-step explanation:

Given:

Future value (F) = $30,000

Number of Year (n) = 15 year = 15 × 12 = 180 month

rate of interest (r) = 3.5% = 0.035 / 12 = 0.0029167

Find:

Deposit value(P)

Computation:

[tex]A = P(1+r)^n\\\\ 30000 = P(1+0.0029167)^{180} \\\\ 30000 = P(1.68917) \\\\ P = 17760.2018[/tex]

Deposit value(P) = $17,760 (Approx)

Answer:

$2,589.52

Step-by-step explanation:

[tex] A = P(1 + \dfrac{r}{n})^{nt} [/tex]

We start with the compound interest formula above, where

A = future value

P = principal amount invested

r = annual rate of interest written as a decimal

n = number of times interest is compound per year

t = number of years

For this problem, we have

P = 2000

r = 0.026

n = 2

t = 10,

and we find A.

[tex] A = $2000(1 + \dfrac{0.026}{2})^{2 \times 10} [/tex]

[tex] A = $2589.52 [/tex]

Compound interest formula:

Total = principal x ( 1 + interest rate/compound) ^ (compounds x years)

Total = 2000 x 1+ 0.026/2^20

Total = $2,589.52

Answer:

The probability of getting an offspring pea that is green is is 0.733

YES, the probability is reasonably close to the expected value of 3/4 (0.750)

Step-by-step explanation:

The formula for calculating the probability of an event is;

P = Favorable Outcome / Sample space

Let A be an event of getting an offspring green peas, B be an event of getting an offspring yellow peas and N be the total number of peas.

number of green peas in an offspring are 350

number of yellow peas in an offspring are 127

total number of peas are 477    

So in the genetic experiment, the number of times event A occurs is 350 and the number times event B occurs is 127

Now the probability of getting an offspring pea that is green is

P = number of green peas / total number of peas

p = n(A)/N

p = 350/477

p = 0.733

So YES, the probability is reasonably close to 3/4 ( 0.750 )

The probability of getting an offspring pea that is green is is 0.733.

YES, the probability is reasonably close to the expected value of 3/4 (0.750)

Answer:

y = 11.19 ; 0.839

Step-by-step explanation:

Given the following :

relationship between hours of TV watched per day (x) and the number of sit-ups a person can do (y)

y = a + bx ; comparing with the linear regression model function

y = predicted variable

a = intercept

b = slope or gradient

x = independent variable

b = -0.89 a = 23.65 r2 = 0.7038

Therefore, if a person watches for 14 hours per day, that is x = 14, the number of sit-ups he can do will be :

y = 23.65 + (-0.89)(14)

y = 23.65 - 12.46

y = 11.19

About 11 sit-ups.

If the r^2 value = 0.7038

Then the Coefficient of regression = r

Will be the square root of r^2

r = sqrt(r^2)

r = sqrt(0.7038)

r =0.8389278 = 0.839

Answer:

a) In the interval  (  55,9  ;   456,7 ) we will find 99,7 % of all values

b) In the interval  (  122,7  ;  389,9 ) we find 95,4 % of all values

Step-by-step explanation:

For a Normal distribution N (μ ; σ ) the Empirical rule establishes that the intervals:

( μ  ±  σ  )          contains 68,3 % of all values

( μ  ±  2σ  )        contains 95,4 % of all values

( μ  ±  3σ  )        contains 99,7 % of all values

If   N ( 256,3 ; 66,8 )

σ  =  66,8        ⇒   3*σ  = 3 * 66,8  = 200,4

Then:     256,3 - 200,4  =  55,9

And        256,3 + 200,4 = 456,7

a) In the interval  (  55,9  ;   456,7 ) we will find 99,7 % of all values

b) 2*σ  = 2 * 66,8  = 133,6

Then  256,3 - 133,6  = 122,7

And    256,3 + 133,6 = 389,90

Then in the interval  (  122,7  ;  389,9 ) we find 95,4 % of all values

Correct question is;

The U.S. Dairy Industry wants to estimate the mean yearly milk consumption. A sample of 21 people reveals the mean yearly consumption to be 74 gallons with a standard deviation of 16 gallons.

a. What is the value of the population mean? What is the best estimate of this value?

b. Explain why we need to use the t distribution. What assumption do you need to make?

c. For a 90 percent confidence interval, what is the value of t?

d. Develop the 90 percent confidence interval for the population mean.

e. Would it be reasonable to conclude that the population mean is 68 gallons?

Answer:

A) Best estimate = 74 gallons

B) because the population standard deviation is unknown. The assumption we will make is that the population follows the normal distribution.

C) t = 1.725

D) 90% confidence interval for the population mean is (67.9772, 80.0228) gallons

E) Yes

Step-by-step explanation:

We are given;

Sample mean; x' = 74

Sample population; n = 21

Yearly Standard deviation; s = 16

A) We are not given the population mean.

So the closest estimate to the population mean would be the sample mean which is 74.

B) We are not given the population standard deviation and as such we can't use normal distribution. So what is used when population standard deviation is not known is called t - distribution table. The assumption we will make is that the population follows the normal distribution.

C) At confidence interval of 90% and DF = n - 1 = 21 - 1 = 20

From t-tables, the t = 1.725

D) Formula for the confidence interval is;

x' ± t(s/√n) = 74 ± 1.725(16/√21) = 74 ± 6.0228 = 67.9772 or 80.0228

Thus 90% confidence interval for the population mean is (67.9772, 80.0228) gallons

E) 68 gallons lies within the range of the confidence interval, thus we can say that "Yes, it is reasonable"

Answer:

Infinite number of solutions.

Step-by-step explanation:

There are an infinite number of solutions.  If you graph both lines, you find they are the same line.  If you multiply the send equation by -4, you’ll end up with the first equation.  I’m not sure what your teacher means by specifying their form.

Answer:

[tex]\large \boxed{3.4 \times 10^{10}\text{ ergs }}[/tex]

Step-by-step explanation:

[tex]\begin{array}{rcl}\log E & = & 11.8 + 1.5M\\& = & 11.8 + 1.5 \times 8.3\\& = & 11.8 + 12.45\\& = & 24.25\\E & = & e^{24.25}\\& = & \mathbf{3.4 \times 10^{10}} \textbf{ ergs}\\\end{array}\\\text{ The energy released was $\large \boxed{\mathbf{3.4 \times 10^{10}}\textbf{ ergs }}$}[/tex]

Responder:

| AB | = 12m

Explicación paso a paso:

Verifique el diagrama en el archivo adjunto.

En el diagrama, se puede ver que el lado FC es igual al lado FB de acuerdo con el triángulo isósceles FBC.

Además, el lado FB es igual a AB ya que son paralelos entre sí.

De la declaración anterior, | FC | = | FB | y | FB | = | AB |

Esto significa | FC | = | FB | = | AB |

Por lo tanto desde | FC | = 12 m, | AB | = 12 m ya que ambos lados son iguales.

De ahí el lado | AB | se mide 12m

Answer:

Hello the options to your question is missing below are the options

 A) if sample means were obtained for a long series of samples, approximately 95 percent of all sample means would be between 10 and 16 miles

B.the unknown population mean is definitely between 10 and 16 miles

C.if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians

D.the unknown population mean is between 10 and 16 miles with probability .95

Answer : if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians  ( c )

Step-by-step explanation:

95%  confidence

interval = 10 to 16 miles

To have 95% confidence signifies that if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians

confidence interval covers a range of samples/values in the interval and the higher the % of the confidence interval the more precise the interval is,

Answer:

mean=502/10=50.2

median=(54+56)2=55

Answer:

1,2 and 6

Step-by-step explanation:

pie symbol

2/3

0.333333....

Answer:

C

Step-by-step explanation:

The area (A) of a circle is calculated as

A = πr² ( r is the radius )

Here r = 18 cm , thus

A = π × 18² = 324π ≈ 1017.9 cm² → C

Answer:

C.) 1017.9 cm²

Step-by-step explanation:

For a given circle

radius (r) = 18 cm

Now,

Area of Circle

= πr²

= 3.14 × (18)² cm

= 3.14 × 324 cm

= 1017.9 cm²

Answer:

x=24

Step-by-step explanation:

3/4(x-8)=12

3/4x-24/4=12

3/4x=18

18 dived by 3/4

x=24

your welcome :)

Answer:

(4) → (1) → (3) → (2)

Step-by-step explanation:

Order of operations in any question are decided by the rule,

P → Parentheses

E → Exponents

D → Division

M → Multiplication

A → Addition

S → Subtract

Following the same rule order of operations will be,

- Take care of anything inside the parentheses.

- Evaluate and raise the exponents

- Multiply or divide. Make sure to do whichever one comes first from left to right.

- Add or Subtract from left to right.

Options are arranged in the order of,

(4) → (1) → (3) → (2)

Answer:

3.25

Step-by-step explanation:

Answer:

One pound of chicken is $1.34

Step-by-step explanation:

So, if 9.5 pounds of chicken is $12.73, all you have to do it divide 12.73 and 9.5. That way, you can see how much each pound is separately! Hopefully this helps!

Answer:

[tex]\huge\boxed{1\ pound\ of\ chicken = \$1.34}[/tex]

Step-by-step explanation:

9.5 pounds of chicken = $12.73

Dividing both sides by 9.5

1 pound of chicken = $12.73 / 9.5

1 pound of chicken = $1.34

Answer:

(a) The probability that X is at most 30 is 0.9726.

(b) The probability that X is less than 30 is 0.9554.

(c) The probability that X is between 15 and 25 (inclusive) is 0.7406.

Step-by-step explanation:

We are given that 11% of all steel shafts produced by a certain process are nonconforming but can be reworked. A random sample of 200 shafts is taken.

Let X = the number among these that are nonconforming and can be reworked

The above situation can be represented through binomial distribution such that X ~ Binom(n = 200, p = 0.11).

Here the probability of success is 11% that this much % of all steel shafts produced by a certain process are nonconforming but can be reworked.

Now, here to calculate the probability we will use normal approximation because the sample size if very large(i.e. greater than 30).

So, the new mean of X, [tex]\mu[/tex] = [tex]n \times p[/tex] = [tex]200 \times 0.11[/tex] = 22

and the new standard deviation of X, [tex]\sigma[/tex] = [tex]\sqrt{n \times p \times (1-p)}[/tex]

                                                                  = [tex]\sqrt{200 \times 0.11 \times (1-0.11)}[/tex]

                                                                  = 4.42

So, X ~ Normal([tex]\mu =22, \sigma^{2} = 4.42^{2}[/tex])

(a) The probability that X is at most 30 is given by = P(X < 30.5)  {using continuity correction}

        P(X < 30.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{30.5-22}{4.42}[/tex] ) = P(Z < 1.92) = 0.9726

The above probability is calculated by looking at the value of x = 1.92 in the z table which has an area of 0.9726.

(b) The probability that X is less than 30 is given by = P(X [tex]\leq[/tex] 29.5)    {using continuity correction}

        P(X [tex]\leq[/tex] 29.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{29.5-22}{4.42}[/tex] ) = P(Z [tex]\leq[/tex] 1.70) = 0.9554

The above probability is calculated by looking at the value of x = 1.70 in the z table which has an area of 0.9554.

(c) The probability that X is between 15 and 25 (inclusive) is given by = P(15 [tex]\leq[/tex] X [tex]\leq[/tex] 25) = P(X < 25.5) - P(X [tex]\leq[/tex] 14.5)   {using continuity correction}

       P(X < 25.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{25.5-22}{4.42}[/tex] ) = P(Z < 0.79) = 0.7852

       P(X [tex]\leq[/tex] 14.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{14.5-22}{4.42}[/tex] ) = P(Z [tex]\leq[/tex] -1.70) = 1 - P(Z < 1.70)

                                                          = 1 - 0.9554 = 0.0446

The above probability is calculated by looking at the value of x = 0.79 and x = 1.70 in the z table which has an area of 0.7852 and 0.9554.

Therefore, P(15 [tex]\leq[/tex] X [tex]\leq[/tex] 25) = 0.7852 - 0.0446 = 0.7406.

Answer:

308/5

Step-by-step explanation:

It can be Written as

= 7 ×(8 + 4/5 )

= 7 × 8 + 7 ×   4/5

= 56 +  28/5

= 280+28

________

       5  

=  308/5

Answer:

[tex]y = -x - 3[/tex]

Step-by-step explanation:

We are trying to get the equation [tex]3x + 3y = -9[/tex] into the form [tex]y = mx+b[/tex], aka slope-intercept form.

To do this we are trying to isolate y.

[tex]3x + 3y = -9[/tex]

Subtract 3x from both sides:

[tex]3y = -9 - 3x[/tex]

Rearrange the terms:

[tex]3y = -3x - 9[/tex]

Divide both sides by 3:

[tex]y = -x - 3[/tex]

Hope this helped!

Answer:

Answer:

96/8 - c

Step-by-step explanation:

96/8 = 12

The average amount of cookies each grandchild would get is 12. However, Cindy gets c less than the average amount. So, it would be 12 - c.

But, it's asking for the original expression. Therefore, the answer would be 96/8 - c.

Answer:

five and forty-four hundredths

Step-by-step explanation:

Answer:

five point four four

Step-by-step explanation:

━━━━━━━☆☆━━━━━━━

▹ Answer

(10, -1)

▹ Step-by-Step Explanation

x - y = 11

2x + y = 19

Sum up the equations:

3x = 30

Divide 3 on both sides:

x = 10

Substitute:

10 - y = 11

y = -1

Solution:

(x, y) (10, -1)

Hope this helps!

CloutAnswers ❁

━━━━━━━☆☆━━━━━━━

Step-by-step explanation:

scatter plot s are similar to line graphs in that they start with mapping quantitive data points. The difference is that with a scatter plot, the decision is made the the individual points should not be connected directly together with a line but, instead express a trend