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1 year ago

Which shows how the distributive property can be used to evaluate 7 times 8 and four-fifths?

Mathematics

2 answers:

ICE Princess25 [194]1 year ago

8 0

Answer:

2 + 2 = fish

Step-by-step explanation:

dedylja [7]1 year ago

3 0

Answer:

its A

Step-by-step explanation:

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According to a survey, 10% of Americans are afraid to fly. Suppose 1100 Americans are sampled. a) What is the probability that 1

JulijaS [17]

Answer:

a) 14.46%

b) 0.00%

c) 1.54%

Step-by-step explanation:

According to the survey, 10% of Americans are afraid to fly.

This means $p=0.10$ and $q=1-0.10=0.90$ .

If 1100 Americans are sampled, then the sample size is $n=1100$ .

The mean of the distribution is $\mu=np$ .

This means $\mu=1100\times 0.10=110$

The standard deviation is $\sigma=\sqrt{npq}$

We substitute the values to get:

$\sigma=\sqrt{1100\times 0.1\times 0.9}=9.95$

a) We want to find the probability that 121 or more Americans in the survey are afraid to fly.

We first apply the continuity correction factor to get: $P(X\ge121)=P(X\:>\:121-0.5)\\P(X\ge121)=P(X\:>\:120.5)$

We now convert to Z-scores to get:

$P(X\:>\:120.5)=P(z\:>\:\frac{120.5-110}{9.95})=1.06\\$

From the standard normal distribution table P(z>1.06)=0.1446

As a percentage, the probability is 14.46%

b) We want to find the probability that 165 or more Americans in the survey are afraid to fly.

We apply the CCF to get:

$P(X\ge165)=P(X\:>\:165-0.5)\\P(X\ge165)=P(X\:>\:164.5)$

We convert to z-scores:

$P(X\:>\:164.5)=P(z\:>\:\frac{164.5-110}{9.95})=5.48$

From the normal distribution, P(z>164.5)=0

c) First, 8% of 1100 is 88.

We want to find the probability that 88 or less Americans in the survey are afraid to fly.

We apply the CCF to get:

$P(X\le88)=P(X\:$

We convert to z-scores:

$P(X\:$

From the normal distribution, P(z>\:-2.16)=0.0154

As a percentage, we get 1.54%

3 0

2 years ago

If each term in the sum a1+a2+a3+...+an is either 7 or 77 and the sum equals 350, which of the following could be equal to n?A.

Svetlanka [38]

Answer:

C. 40

Step-by-step explanation:

Let us say there are x 7's and y 77's.

We have been given that each term in the sum a1+a2+a3+...+an is either 7 or 77 and the sum equals 350. We are asked to find the value of n.

Since the sum of all numbers is 350, so we can represent this information in an equation as:

$7x+77y=350$

The only integer solutions for the equation $7x+77y=350$ are 10, 20, 30, 40, 50 .

So, there can be these many terms: 10 or 20 or 30 or 40 or 50 .

The given option only contains 40, so 40 would be the answer. For 40 terms to be there, there has to be 39 sevens and 1 seventy-seven.

Let us verify our answer.

$7x+77y=350$

$7(39)+77(1)=350$

$273+77=350$

$350=350$

Therefore, the total terms (n) could be equal to 40 and option C is the correct choice.

8 0

2 years ago

A 120 watt light bulb uses about 0.1 kilowatt of electricity per hour.if electricity costs $0.20 per kilowatt hour how much does

Ksivusya [100]

A 120 watt light bulb uses about 0.1 kilowatt of electricity per hour.if electricity costs $0.20 per kilowatt hour. Let's solve how much does it cost to have a bulb on for an hour. => 120 watt = 0.1 kilowatt per hour which costs 0.20 per kilowatt per => 0.1 kilowatt per hour * 0.20 = 0.02 dollars in an hour.

8 0

1 year ago

Read 2 more answers

We know that a triangle with side lengths x2 -1, 2x, and x2 1 is a right triangle. Using those side lengths, find the missing tr

Olenka [21]

Least to greatest, the triples are (2x, x²-1, x²+1). Thus the value in the first column of the table is half the value of the first of the triples. Your completed table will be

$\begin{array}{cc}\text{x-value}&\text{triple}\\3&\bf{(6,8,10)}\\\bf{4}&(8,15,17)\\5&\bf{(10,24,26)}\\\bf{6}&(12,35,36)\end{array}$