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3 years ago

What time is 10 minutes before 8:00 in the morning? *

Mathematics

2 answers:

strojnjashka [21]3 years ago

6 0

Answer: 7:50 AM

Step-by-step explanation:

The clock goes to 60 minutes so if you subtract 10 from 8:00 AM

It will start at 7:60

7:60-10 is 7:50

IRISSAK [1]3 years ago

4 0

Answer:

7:50 AM

Step-by-step explanation:

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Value of x? Help lol

sashaice [31]

Answer:

128

Step-by-step explanation:

well x be 128 cause their vertical angles

4 0

3 years ago

Read 2 more answers

Wins 1975, loses 339, ties 10. What is my percent of wins?

dimaraw [331]

1975/1975+339+10

Wins/Total

1975/2324=0.8498

Convert to percent by moving decimal point up 2

Percent of wins: 84.98%

6 0

3 years ago

Twenty different books are to be put on five book shelves, each of which holds at least twenty books.

olya-2409 [2.1K]

Answer:

(a) 10,626 different arrangements

(b) 95,367,431,640,625 different arrangements

Step-by-step explanation:

(a) How many different arrangements are there if you only care about the number of books on the shelves (and not which book is where)?

We use the combination formula for this

C(n , r) = n + r - 1C r - 1

n = 20

r = 5

= 20 + 5 - 1 C 5-1

= 24C4

= 24!/4 ! × (24 - 4)

= 24!/4! × 20!

= 10,626 arrangements

(b) How many different arrangements are there if you care about which books are where, but the order of the books on the shelves doesn't matter?

Since the order of the books on the shelves does not matter,

The calculation is given as

5²⁰ = 95,367,431,640,625 arrangements

Since order matters now

Step 1

We use the combination formula for this

C(n , r) = n + r - 1C r - 1

n = 20

r = 5

= 20 + 5 - 1 C 5-1

= 24C4

= 24!/4 ! × (24 - 4)

= 24!/4! × 20!

= 10,626

Step 2

We find the factorial of the number books

= 20!

= 2,432,902,008,176,640,000

Step 3

The different arrangements there are if the order on the shelves does matter is calculated

= 10,626 × 2,432,902,008,176,640,000

= 2.5852017 × 10²² different arrangements

8 0

2 years ago

g If a random sample of 18 deliveries was selected instead and the standard deviation of these delivery times was found to be 9.

lana [24]

Answer:

We can use the z score formula given by:

$z= \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

If we use this formula we got:

$z=\frac{21-20}{\frac{9.31}{\sqrt{18}}}= 0.456$

$z=\frac{25-20}{\frac{9.31}{\sqrt{18}}}= 2.279$

And using a calculator, excel or the normal standard table and we have that:

$P(0.456$

Step-by-step explanation:

We assume this previous info: It is known that the amounts of time required for room-service delivery at a certain Marriott Hotel are Normally distributed with the average delivery time of 20 minutes.

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 Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the delivery times of a population, and for this case we know the distribution for X is given by:

$X \sim N(20,9.31)$