Find the measure of b. A. 80 B. 70 C. 40 D. 20

A freight train completes its journey of 150 miles 1 hour earlier if its original speed is increased by 5 miles/hour what is the

vlabodo [156]

<span>A freight train completes its journey of 150 miles 1 hour earlier if its original speed is increased by 5 miles/hour. What is the train’s original speed?
***
let x=original speed
x+5=increased speed
travel time=distance/speed
..
lcd:x(x+5)
150(x+5)-150x=x(x+5)
150x+750-150x=x^2+5x
x^2+5x-750=0
(x-25)(x+30)=0
x=25
What is the train’s original speed? 25 mph</span>

7 0

2 years ago

Of the 27 players trying out for the school basketball team, 8 are more than 6 feet tall and 7 have good aim. What is the probab

Komok [63]

Of the 27 players trying out for the school basketball team, 8 are more than 6 feet tall and 7 have good aim. What is the probability that the coach would randomly pick a player over 6 feet tall or a player with a good aim? Assume that no players over 6 feet tall have good aim. A. 7/15 B. 6/15 C. 7/9 D. 5/9

The Answer Is

--------5/9--------

5 0

2 years ago

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers have maintained careful records

madreJ [45]

Answer:

For this case we have the following info related to the time to prepare a return

$\mu =90 , \sigma =14$

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard deviation would be:

$\sigma_{\bar X} =\frac{14}{\sqrt{49}}= 2$

And the best answer would be

b. 2 minutes

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

Solution to the problem

For this case we have the following info related to the time to prepare a return

$\mu =90 , \sigma =14$

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard deviation would be:

$\sigma_{\bar X} =\frac{14}{\sqrt{49}}= 2$

And the best answer would be

b. 2 minutes

3 0

2 years ago

Find the range of y=3/2cos4x-1

MrRissso [65]

Answer:

Range = [- 2.5, 0.5] = [ - 5/2, 1/2]

Step-by-step explanation:

Smallest value of cos α = - 1,

largest value of cos α = 1.

When cos 4x = - 1, y=3/2cos4x-1 = 3/2*(-1) - 1 = - 5/2 = - 2 1/2 = - 2.5

When cos 4x = 1, y=3/2cos4x-1 = 3/2*1 - 1 = 1/2 = 0.5

Range = [- 2.5, 0.5] = [ - 5/2, 1/2]

5 0

2 years ago

The profits for a business can be represented as a function p(x)=110+25x for the month of January and q(x)=15x+85 for the month

mrs_skeptik [129]

To find the total profit, add p(x) and q(x):
(110 + 25x) + (15x + 85)
15x + 25x + 110 + 85 --> group like terms
40x + 195 --> add like terms
p(x) + q(x) = 40x + 195 --> This is the function that represents the total profit for January and February

4 0

2 years ago

Read 2 more answers