Please ⟟ need help fast

mixas84 [53]

The answer would be 14x+5 I’m pretty sure

5 0

3 years ago

How many 7-digit numbers are there where all the digits are different and in increasing order? for example, the numbers 1345689

frutty [35]

For this problem,we use the Fundamental Counting Principle. You know that there are 7 digits in a number. In this principle, you have to multiply the possible numbers for every digit. If the first number cannot be zero, then there are 9 possible numbers. So, the value for the first digit is 9. The second digit could be any number but less of 1 because it was used in the 1st digit. So, that would be 10 - 1 = 9. The third digit must be the value in the second digit less than 1. That would be 9 - 1 = 8. And so on and so forth. The solution would be:

9×9×8×7×6×5×4 = 544,320 7-digit numbers

4 0

3 years ago

a jogger runs 4 miles per hour faster downhill than uphill. if the jogger can run 5 miles downhill in the same time that it take

Serga [27]

Answer: the rate uphill is 6 mph.

The rate downhill is 10 mph

Step-by-step explanation:

Let x represent the rate at which the jogger ran uphill.

The jogger runs 4 miles per hour faster downhill than uphill. This means that speed at which the jogger ran downhill is (x + 4) mph

Time = distance/speed

if the jogger can runs 5 miles downhill, then the time taken to run downhill is

5/(x + 4)

At the same time, the jogger runs 3 miles uphill. It means that the time taken to run uphill is

3/x

Since the time is the same, it means that

5/(x + 4) = 3/x

Cross multiplying, it becomes

5 × x = 3(x + 4)

5x = 3x + 12

5x - 3x = 12

2x = 12

x = 12/2

x = 6

The rate downhill is 6 + 4 = 10 mph

8 0

4 years ago

Read 2 more answers

The front of an A-frame house is in the shape of a triangle.The height of the house is 20 feet.The area of the front of a A-fram

ipn [44]

600 divided by 20=30
30x2=60 which is the answer

equation= 600=2x area divied by height

7 0

4 years ago

The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than av

34kurt

Answer:

Probability that the 50 randomly selected laptops will have a mean replacement time of 3.1 years or less is 0.0092.

Yes. The probability of this data is unlikely to have occurred by chance alone.

Step-by-step explanation:

We are given that the replacement times for the model laptop of concern are normally distributed with a mean of 3.3 years and a standard deviation of 0.6 years.

He then randomly selects records on 50 laptops sold in the past and finds that the mean replacement time is 3.1 years.

Let M = sample mean replacement time

The z-score probability distribution for sample mean is given by;

Z = $\frac{ M-\mu}{\frac{\sigma}{\sqrt{n} } }} }$ ~ N(0,1)

where, $\mu$ = population mean replacement time = 3.3 years

$\sigma$ = standard deviation = 0.6 years

n = sample of laptops = 50

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) 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.

Now, Probability that the 50 randomly selected laptops will have a mean replacement time of 3.1 years or less is given by = P(M $\leq$ 3.1 years)

P(M $\leq$ 3.1 years) = P( $\frac{ M-\mu}{\frac{\sigma}{\sqrt{n} } }} }$ $\leq$ $\frac{ 3.1-3.3}{\frac{0.6}{\sqrt{50} } }} }$ ) = P(Z $\leq$ -2.357) = 1 - P(Z $\leq$ 2.357)

= 1 - 0.99078 = 0.0092 or 0.92%

So, in the z table the P(Z $\leq$ x) or P(Z < x) is given. So, the above probability is calculated by looking at the value of x = 2.357 in the z table which will lie between x = 2.35 and x = 2.36 which has an area of 0.99078.

Hence, the required probability is 0.0092 or 0.92%.

Now, based on the result above; Yes, the computer store has been given laptops of lower than average quality because the probability of this data is unlikely to have occurred by chance alone as the probability of happening the given event is very low as 0.92%.

8 0

4 years ago