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4 years ago

Given the two expressions shown below:

1 answer:

5 0

A is irrational but b is rational. This is because for b you can work out both square root of 64 (8) and square root of 4 (2). But for a, the square root of 5 is an irrational number :)

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Barry arrives at the hotel each morning at 7:00am. Today he will stay late to oversee a party in the ballroom. He will leave the

Dmitry_Shevchenko [17]

im pretty sure 13 hours he would spend in the hotel, 7 am to 1 am, hope this helps^^

4 0

3 years ago

15 men can do a piece of work in 80 days. If 5 more men are added, how long will it take to complete same piece of work?

tresset_1 [31]

Answer:

Step-by-step explanation:

This is an inverse proportion.

men = k / Time So first we need to find k

k = men * Time Substitute values

k = 15*80

k = 1200 Notice the units are man days.

Now what happens if we increase the number of men to 20? What happens to the number of days.

20 = 1200 / time Multiply both sides by time

20*time = 1200 Now divide by 20

time = 1200/20

Answer: time = 60 days

4 0

2 years ago

4.62x10 1.2x 10 What’s the scientific notation

MArishka [77]

46200000000.
12000000000.
you just move the decimal 10 places to the right

5 0

3 years ago

Which statement is true about the equation 22-2=m-7?

Liono4ka [1.6K]

22-2=m-7.
first you subtract 22-2 thats 20.
then youtake 20 and subtract it by 7 but in order to do that you have to make 20 negative.
m-7
- 20
this equals m-20

4 0

3 years ago

Suppose that the population mean for income is $50,000, while the population standard deviation is 25,000. If we select a random

Fudgin [204]

Answer:

Probability that the sample will have a mean that is greater than $52,000 is 0.0057.

Step-by-step explanation:

We are given that the population mean for income is $50,000, while the population standard deviation is 25,000.

We select a random sample of 1,000 people.

Let $\bar X$ = sample mean

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

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

where, $\mu$ = population mean = $50,000

$\sigma$ = population standard deviation = $25,000

n = sample of people = 1,000

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.

So, probability that the sample will have a mean that is greater than $52,000 is given by = P( $\bar X$ > $52,000)

P( $\bar X$ > $52,000) = P( $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ > $\frac{52,000-50,000}{\frac{25,000}{\sqrt{1,000} } }$ ) = P(Z > 2.53) = 1 - P(Z $\leq$ 2.53)

= 1 - 0.9943 = 0.0057

Now, 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 = 2.53 in the z table which has an area of 0.9943.

Therefore, probability that the sample will have a mean that is greater than $52,000 is 0.0057.

5 0

3 years ago