2. How many sixteenths are in 9/16? *

The mean waiting time at the drive-through of a fast-food restaurant from the time the food is ordered to when it is received is

alexira [117]

Answer:

a) And if we replace we got: $\bar X= 78$

$s = 15.391$

b) $78-3.25\frac{15.391}{\sqrt{10}}=62.182$

$78-3.25\frac{15.391}{\sqrt{10}}=93.818$

So on this case the 99% confidence interval would be given by (62.182;93.818)

Step-by-step explanation:

Dataset given: 109 67 58 76 65 80 96 86 71 72

Part a

For this case we can calculate the sample mean with the following formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And if we replace we got: $\bar X= 78$

And the deviation is given by:

$s =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And if we replace we got $s = 15.391$

Part b

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=10-1=9$

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,9)".And we see that $t_{\alpha/2}=3.25$

Now we have everything in order to replace into formula (1):

$78-3.25\frac{15.391}{\sqrt{10}}=62.182$

$78-3.25\frac{15.391}{\sqrt{10}}=93.818$

So on this case the 99% confidence interval would be given by (62.182;93.818)

8 0

3 years ago

The level of nitrogen oxides (NOX) in the exhaust after 50,000 miles or fewer of driving of cars of a particular model varies No

Greeley [361]

Answer:

For a level of 0.0174 or more of nitrogen oxide, the probability of fleet is 0.01.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 0.02 g/mi

Standard Deviation, σ = 0.01 g/mi

Sample size, n = 81

We are given that the distribution of level of nitrogen oxides is a bell shaped distribution that is a normal distribution.

Standard error due to sampling:

$=\dfrac{\sigma}{\sqrt{n}} = \dfrac{0.01}{\sqrt{81}} = 0.0011$

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

We have to find the value of x such that the probability is 0.01

P(X > x)

$P( X > x) = P( z > \displaystyle\frac{x - 0.02}{0.0011})=0.01$

$= 1 -P( z \leq \displaystyle\frac{x - 0.02}{0.0011})=0.01$

$=P( z \leq \displaystyle\frac{x - 0.02}{0.0011})=0.99$

Calculation the value from standard normal z table, we have,

$\displaystyle\frac{x - 0.02}{0.0011} = -2.326\\\\x = 0.0174$

For a level of 0.0174 or more of nitrogen oxide, the probability of fleet is 0.01.

5 0

3 years ago

ou draw one card from a 52-card deck. Then the card is replaced in the deck and the deck is shuffled, and you draw again. Find

julsineya [31]

Answer: Our required probability is $\dfrac{1}{52}$

Step-by-step explanation:

Since we have given that

Number of cards in a deck = 52

Number of nines = 4

Number of hearts = 13

It is the case of replacement.

Probability of drawing a nine the first time and a hear the second time is given by

$\dfrac{4}{52}\times \dfrac{13}{52}\\\\=\dfrac{1}{13}\times \dfrac{1}{4}\\\\=\dfrac{1}{52}$

Hence, our required probability is $\dfrac{1}{52}$

3 0

3 years ago

Which value represents a horizontal shift (left and right) in the following function y=a*sin(bx-c)+d

grigory [225]

The value is C because it represents the shift

5 0

3 years ago

Expand the polynomial:<br> (5a+1/5 b)^2

WINSTONCH [101]

Expand the following:
(5 a + b/5)^2

(5 a + b/5) (5 a + b/5) = (5 a) (5 a) + (5 a) (b/5) + (b/5) (5 a) + (b/5) (b/5):
5×5 a a + (5 a b)/5 + (5 b a)/5 + (b b)/(5×5)

(5 a b)/5 = 5/5×a b = a b:
5×5 a a + a b + (5 b a)/5 + (b b)/(5×5)

(b×5 a)/5 = 5/5×b a = b a:
5×5 a a + a b + b a + (b b)/(5×5)

Combine powers. (b b)/(5×5) = (b^(1 + 1))/(5×5):
5×5 a a + a b + b a + (b^(1 + 1))/(5×5)

1 + 1 = 2:
5×5 a a + a b + b a + (b^2/5)/5

5 a×5 a = 5×5 a^2:
5×5 a^2 + a b + b a + (b^2/5)/5

5×5 = 25:
Answer: 25 a^2 + a b + b a + (b^2/5)/5

3 0

3 years ago

Read 2 more answers