I need help doing this

Perform the indicated operations; reduce the answer to lowest terms.

kow [346]

a. 9/10

explanation:

• the denominators (bottom number) are the same so there is no need to change to a common factor

• because the fractions have common factors, you add the top numbers (3+6) to get 9

• then you put the top number over the 10 (9/10) and it’s simplified as much as possible

b. 3/4

explanation:

• each denominator (bottom term) is a factor of 12 so you have to change each fraction to #/12

• to change 1/3, you multiply the top and bottom numbers by 4 (1x4 & 3x4 = 4/12)

• to change 1/4, you multiply the top and bottom numbers by 3 (1x3 & 4x3 = 3/12)

• to change 1/6, you multiple the top and bottom numbers by 2 (1x2 & 6x2 = 2/12)

• then you add each of the top numbers (4+3+2) and put it over the common denominator (12) to get 9/12

- both 9 & 12 are divisible by 3, so you simply by dividing both by 3 to get 3/4

c. 1/3

explanation:

•the denominators are the same, so you subtract 5-3 without changing the denominator & you get 2/6

• then, because both numbers are divisible by 2, you divide both by 2 and get 1/3

3 0

3 years ago

An automobile company wants to determine the average amount of time it takes a machine to assemble a car. A sample of 40 times y

aksik [14]

Answer:

A 98% confidence interval for the mean assembly time is [21.34, 26.49] .

Step-by-step explanation:

We are given that a sample of 40 times yielded an average time of 23.92 minutes, with a sample standard deviation of 6.72 minutes.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample average time = 23.92 minutes

s = sample standard deviation = 6.72 minutes

n = sample of times = 40

$\mu$ = population mean assembly time

Here for constructing a 98% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, a 98% confidence interval for the population mean, $\mu$ is;

P(-2.426 < $t_3_9$ < 2.426) = 0.98 {As the critical value of z at 1% level

of significance are -2.426 & 2.426}

P(-2.426 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.426) = 0.98

P( $-2.426 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

P( $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

98% confidence interval for $\mu$ = [ $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $23.92-2.426 \times {\frac{6.72}{\sqrt{40} } }$ , $23.92+2.426 \times {\frac{6.72}{\sqrt{40} } }$ ]

= [21.34, 26.49]

Therefore, a 98% confidence interval for the mean assembly time is [21.34, 26.49] .

7 0

3 years ago

A cyclist rides her bike at a rate of 30 kilometers per hour. What is this rate in kilometers per minute? How many kilometers wi

SIZIF [17.4K]

5 kilometers for 10 minutes
60 minutes= 1 hour
30 kilometers divided by 60 minutes=0.5
0.5*10 minutes= 5 kilometers for 10 minutes

5 0

3 years ago

Two boats leave a port at the same time, one going north and the other traveling south. The northbound boat travels 18 mph fast

shutvik [7]

Answer:

10 hours

Step-by-step explanation:

Two boats leave a port at the same time, one going north and the other traveling south.

Southbound boat rate = 40 mph

The northbound boat travels 18 mph faster than the southbound boat.

Northbound boat rate = 40 + 18 = 58 mph

Two boats rate = 40 + 58 = 98 mph (this means they are apart 98 km after one hour)

Total distance = 980 miles

Total rate = 98 mph

Time $=980:98=10$ hours

3 0

3 years ago

Help i am stuck on a question and i still dont know how to do it

drek231 [11]

Answer:

i think it is 1/26

Step-by-step explanation:

6 0

2 years ago

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