The scale of a map is 1 cm: 75 km. What is the actual distance between two towns that are 4 cm apart on the map?

Writing to Explain Trey wrote 9.009 -0.01 = 9.008. Is his answer correct?<br> Why or why not?

bekas [8.4K]

Answer:

No it is not correct.

Step-by-step explanation:

9.009-0.01=8.999

6 0

2 years ago

The heights of 40 randomly chosen men are measured and found to follow a normal distribution. An average height of 175 cm is obt

AVprozaik [17]

Answer:

95% two-sided confidence interval for the true mean heights of men is [168.8 cm , 181.2 cm].

Step-by-step explanation:

We are given that the heights of 40 randomly chosen men are measured and found to follow a normal distribution.

An average height of 175 cm is obtained. The standard deviation of men's heights is 20 cm.

Firstly, the pivotal quantity for 95% confidence interval for the true mean is given by;

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

where, $\bar X$ = sample average height = 175 cm

$\sigma$ = population standard deviation = 20 cm

n = sample of men = 40

<em>Here for constructing 95% confidence interval we have used One-sample z test statistics as we know about population standard deviation.</em>

So, 95% confidence interval for the true mean, $\mu$ is ;

P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5%

level of significance are -1.96 & 1.96}

P(-1.96 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.96) = 0.95

P( $-1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ ) = 0.95

<u>95% confidence interval for </u> $\mu$ = [ $\bar X-1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ , $\bar X+1.96 \times }{\frac{\sigma}{\sqrt{n} } }$ ]

= [ $175-1.96 \times }{\frac{20}{\sqrt{40} } }$ , $175+1.96 \times }{\frac{20}{\sqrt{40} } }$ ]

= [168.8 cm , 181.2 cm]

Therefore, 95% confidence interval for the true mean height of men is [168.8 cm , 181.2 cm].

<em>The interpretation of the above interval is that we are 95% confident that the true mean height of men will be between 168.8 cm and 181.2 cm.</em>

3 0

3 years ago

Determine if the set of ordered pairs is a relation or a function.

Inga [223]

to be a function, each input can have only one output. For these points, each x has only one y, so it it a function. A relation, just describes x to y, so it is both

3 0

3 years ago

you have nine coins: a collection of pennies, nickels, dimes, and quarters having a total value of $1.02, with at least one coin

raketka [301]

1 dime is required to make $1.02 cents using 9 coins collections

<h3>How to solve</h3>

<u>Given data</u>

9 coins

a collection of pennies, nickels, dimes, and quarters

total of $1.02 with at least one coin of each type

solution

$1.02 = 102cents

1 penny = 1 cent

1 nickel = 5 cents

1 dime = 10 cents

1 quarter = 25 cents

having one coin of each means 4 coins which is equal to:

1 + 5 + 10 + 25 = 41 cents (fulfilling the first condition remaining 5 coins)

102 - 41 = 61

balancing the remaining coins to make up 61, we first get a penny to reduce the amount 60 cents ( 4 coins remaining )

hence we have

2*25 +2*5 = 60 cents ( 2quarters 2 nickel)

in total we have

2 pennies + 3 nickels + 1 dime + 3 quarters = 9 coins

2 * 1 + 3 * 5 + 1 * 10 + 3 * 25 = 102 cents

Therefore 1 dime is required to make $1.02 cents using 9 coins collections

Read more on dimes here: brainly.com/question/435257

#SPJ1

3 0

1 year ago

Help! 18 points!

Dmitry [639]

C. is the answer bc 3+3x3 is 3 + 9= 12
and -4x3 + 3x3 which is -12 + 9= -3

5 0

4 years ago

Read 2 more answers