XY and BD are parallel lines.

Evaluate the expression.<br> 7.4+6 - 12:4<br><br><br> Plz help me

juin [17]

Answer:

7 . 4 + 6 - 12 : 4 = 31

Step-by-step explanation:

* To solve this problem lets revise the order of operations in

mathematics

- The operations are:

# Addition

# Subtraction

# Multiplication

# Division

# Exponentiation

# Grouping ⇒ Parenthesis or brackets

- The order of these operations is:

# Parenthesis

# Exponents

# Multiplication and Division which comes first from left to right

# Addition and Subtraction which comes first from left to right

- There is a word made from the first letter of each operation

PEMDAS to remember the order of operations

* Lets solve the problem

∵ 7 . 4 + 6 - 12 : 4

∵ The (.) means multiply the numbers

∵ The symbol (:) means divided the numbers

∴ At first multiply 7 by 4 and divide 12 by 4

∴ (7 × 4) + 6 - (12 ÷ 4)

∴ 28 + 6 - 3

∵ Addition comes before subtraction from the left

∴ (28 + 6) - 3

∴ 34 - 3 = 31

∴ 7 . 4 + 6 - 12 : 4 = 31

4 0

3 years ago

A psychological experiment was conducted to investigate the length of time (time delay) between the administration of a stimulus

aleksklad [387]

Answer:

The P-value of this sample is 0 and is less than the significance level (0.05), so the effect is significant and the null hypothesis is rejected.

As there is significant evidence to reject $H_0: \mu= 1.6$ , we can say that there is significant evidence to claim that the mean time delay for the hypothetical population of all persons who may be subjected to the stimulus differs from 1.6 seconds.

The significance level for this test is 0.05.

Step-by-step explanation:

In this case, we want to prove if there is significant evidence that the mean differs from 1.6 seconds. That is the same as having evidence to reject the the hypothesis $H_0:\mu= 1.6$ (the null hypothesis always have the equal sign).

We have to test the null hypothesis

$H_0:\mu= 1.6$

The significance level for this test is 0.05

Calculation of the t-statistic:

$t=\frac{M-\mu}{s/\sqrt{n}} =\frac{2.2-1.6}{0.57/\sqrt{36}} =\frac{0.6}{0.063}= 9.47$

If we look up in a t-table for t=9.47 and df=(36-1)=35, we get this value appears with a probability of zero. A large number like that is very unlikely to happen.

The P-value of this sample is 0 and is less than the significance level (0.05), so the effect is significant and the null hypothesis is rejected.

As there is significant evidence to reject $H_0: \mu= 1.6$ , we can say that there is significant evidence to claim that the mean time delay for the hypothetical population of all persons who may be subjected to the stimulus differs from 1.6 seconds.

6 0

3 years ago

Abigail mixes 2/3 pounds of walnuts with 3/5 pound of dried fruit. To create more of the same mixture, how many pounds of walnut

nignag [31]

1 1/9

To figure out how much walnuts to a pound of dried fruit you’d need to do proportions. So we cross multiply:

2/3 = X
—————- —————-
3/5 = 1

You multiply diagnols 2/3 x 1 = 2/3
3/5 times x is 3/5x.

2/3 = 3/5x. Isolate the variable. Divide 3/5 on both sides cancel out 3/5. 2/3 divide by 3/5 is 2/3 x 5/3 which is 10/9 which equals 1 1/9.

So for 1 lb of dried fruit you need 1 1/9 lb of walnuts to maintain the same mixture

7 0

3 years ago

A vehicle travels a distance of 5t4 − 10t2 + 6 miles in t + 2 minutes.

Dvinal [7]

Answer:

Step-by-step explanation: