I need him with this

Gina bought 2.5 pounds of peaches that cost $1.38 per pound at the grocery store. Amy went to the local farmer’s market and purc

patriot [66]

Gina spent $3.45 in total. amy spent $3.43 in total. so gina spent more money and she spent 2 cents more

4 0

3 years ago

Read 2 more answers

The taxi and takeoff time for commercial jets is a random variable x with a mean of 8.9 minutes and a standard deviation of 2.9

Eva8 [605]

Answer:

a) 0.2981 = 29.81% probability that for 37 jets on a given runway, total taxi and takeoff time will be less than 320 minutes.

b) 0.999 = 99.9% probability that for 37 jets on a given runway, total taxi and takeoff time will be more than 275 minutes

c) 0.2971 = 29.71% probability that for 37 jets on a given runway, total taxi and takeoff time will be between 275 and 320 minutes

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 8.9 minutes and a standard deviation of 2.9 minutes.

This means that $\mu = 8.9, \sigma = 2.9$

Sample of 37:

This means that $n = 37, s = \frac{2.9}{\sqrt{37}}$

(a) What is the probability that for 37 jets on a given runway, total taxi and takeoff time will be less than 320 minutes?

320/37 = 8.64865

Sample mean below 8.64865, which is the p-value of Z when X = 8.64865. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{8.64865 - 8.9}{\frac{2.9}{\sqrt{37}}}$

$Z = -0.53$

$Z = -0.53$ has a p-value of 0.2981

0.2981 = 29.81% probability that for 37 jets on a given runway, total taxi and takeoff time will be less than 320 minutes.

(b) What is the probability that for 37 jets on a given runway, total taxi and takeoff time will be more than 275 minutes?

275/37 = 7.4324

Sample mean above 7.4324, which is 1 subtracted by the p-value of Z when X = 7.4324. So

$Z = \frac{X - \mu}{s}$

$Z = \frac{7.4324 - 8.9}{\frac{2.9}{\sqrt{37}}}$

$Z = -3.08$

$Z = -3.08$ has a p-value of 0.001

1 - 0.001 = 0.999

0.999 = 99.9% probability that for 37 jets on a given runway, total taxi and takeoff time will be more than 275 minutes.

(c) What is the probability that for 37 jets on a given runway, total taxi and takeoff time will be between 275 and 320 minutes?

Sample mean between 7.4324 minutes and 8.64865 minutes, which is the p-value of Z when X = 8.64865 subtracted by the p-value of Z when X = 7.4324. So

0.2981 - 0.0010 = 0.2971

0.2971 = 29.71% probability that for 37 jets on a given runway, total taxi and takeoff time will be between 275 and 320 minutes

7 0

3 years ago

I need help please with this 1 problem

Lyrx [107]

Answer:

See below, please

Step-by-step explanation:

We know

$f(x) = {x}^{2} + 3x - 7$

$g(x) = 3x + 5$

$h(x) = 2 {x}^{2} - 4$

Hence

$f(g(x))$

$= {(3x + 5)}^{2} + 3 \times (3x + 5) - 7$

$= (9 {x}^{2} + 30x + 25) + (9x + 15) - 7$

$= 9 {x}^{2} + 39x + 33$

$h(g(x))$

$= 2 \times {(3x + 5)}^{2} - 4$

$2 \times (9 {x}^{2} + 30x + 25) - 4$

$= 18 {x}^{2} + 60x + 50 - 4$

$= 18 {x}^{2} + 60x + 46$

$(h - f)(x)$

$= h(x) - f(x)$

$= (2 {x}^{2} - 4) - ( {x}^{2} + 3x - 7)$

$= {x}^{2} - 3x + 3$

$(f + g)(x)$

$= f(x) + g(x)$

$= ( {x}^{2} + 3x - 7) + (3x + 5)$

$= {x}^{2} + 6x - 2$

5 0

2 years ago

Error Analysis your friend evaluate (10-5)/5 and gets 9 for an answer. Explain your friend's error

alexandr402 [8]

Answer:

REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEeeeeEEEEEEEEEEEEeeeeeee make sure you thank it.

Step-by-step explanation:

7 0

4 years ago

Which expression is equivalent to (xy2x−3y)4?

lianna [129]

Answer:

4x2y2−12y

Step-by-step explanation:

Write the problem as a mathematical expression. ( x y 2 x − 3 y ) ⋅ 4 Multiply x by x by adding the exponents. ( x 2 y 2 − 3 y ) ⋅ 4 Simplify by multiplying through. 4 ⋅ ( x 2 y 2 ) − 12 y Remove parentheses. 4 x 2 y 2 − 12 y

6 0

2 years ago