7. Lesa spent $25 at the grocery store.

Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 141 millimeters,

tiny-mole [99]

Answer:

Probability that the sample mean would be greater than 141.4 millimetres is 0.3594.

Step-by-step explanation:

We are given that Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 141 millimetres, and a standard deviation of 7.

A random sample of 39 steel bolts is selected.

Let $\bar X$ = sample mean diameter

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 diameter = 141 millimetres

$\sigma$ = standard deviation = 7 millimetres

n = sample of steel bolts = 39

Now, Percentage the sample mean would be greater than 141.4 millimetres is given by = P( $\bar X$ > 141.4 millimetres)

P( $\bar X$ > 141.4) = P( $\frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } } }$ > $\frac{141.4-141}{\frac{7}{\sqrt{39} } } }$ ) = P(Z > 0.36) = 1 - P(Z $\leq$ 0.36)

= 1 - 0.6406 = 0.3594

The above probability is calculated by looking at the value of x = 0.36 in the z table which has an area of 0.6406.

8 0

3 years ago

You are fundraising for the schools track team by selling clothing. The first day, you sell 13 t-shirts and 17 pairs of shorts f

Anastasy [175]

Answers:

one t-shirt costs $10

one pair of shorts costs $15

============================================================

Explanation:

x = cost of one t-shirt

y = cost of one pair of shorts

13x+17y = 385 is the first equation because 13x represents the money you get from selling 13 shirts, and the 17y represents the amount you get from selling 17 shorts. The total 13x+17y is given to be $385

The second equation is 13x+12y = 310 for similar reasoning, but this time you sell 12 shorts this time and you get $310 in revenue.

The system of equations we have is:

$\begin{cases}13x+17y = 385\\13x+12y=310\end{cases}$

There are a few ways to solve this system. Possibly the quickest method is to note that the 13x shows up twice, so we can subtract straight down to eliminate the x terms

So,

13x-13x becomes 0x or just 0, and the x terms go away.
17y-12y becomes 5y
385-310 becomes 75

After those three subtractions, we have the equation 5y = 75 which solves to y = 15 after dividing both sides by 5. This means the cost of one pair of shorts is $15

Plug this y value into any equation involving x and y, and solve for x

13x+17y = 385

13x+17(15) = 385

13x+255 = 385

13x = 385-255

13x = 130

x = 130/13

x = 10

Therefore, each t-shirt costs $10

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To help verify the answer, plug (x,y) = (10,15) into each equation. We should end up with a true result after simplifying both sides.

Start with the first equation

13x+17y = 385

13(10)+17(15) = 385

130+255 = 385

385 = 385

We get a true result which confirms the first equation.

Repeat for the second equation.

13x+12y = 310

13(10)+12(15) = 310

130+180 = 310

310 = 310

Both equations are true so (x,y) = (10, 15) has been fully confirmed.

6 0

2 years ago

Damian works after school. Each

nadya68 [22]

Answer:

f(x) = 12x = 10

Step-by-step explanation:

We need a linear equation in the slope-intercept form.

y = mx + b

where y = total pay, m = hourly salary, x = number of hours worked, and b = y-intercept, or initial value

Let's look in the table.

1 hour: $22

2 hours: $34

The difference in pay between 1 hour and 2 hours is $34 - $22 = $12.

The difference in time between 1 hour and 2 hours is 1 hour.

In 1 hour he earns $12. That means the slope is 12.

We know he earns $22 for working a total of 1 hour.

Start at 1 hour and $22 on the table.

Subtract 1 hour from 1 hour to get 0 hours.

Subtract $12 form $22 to get $10.

That means for 0 hours he gets $10. b = 10

The equation is

y = 12x + 10

In function form, we have:

f(x) = 12x = 10

5 0

2 years ago

Use the distributive property to remove the parentheses.

nlexa [21]

Answer:

Step-by-step $12c^{3} -40c^{8}$ explanation:

8 0

3 years ago

Please help!!!!!!!!!!!!!!!!!!!!!!!!!!

Triss [41]

Answer:

The Blue box is your answer

Step-by-step explanation:

Multiply 4, 8, and 7 and you get 224. The problem states that it should not be over 250, and 224 is not over 250. So the blue box is your best go.

5 0

2 years ago