He needs to buy 198 tiles. To find this, break down the dimensions of the room from feet into inches then divide each number(264in and 192in) by 16in. This gives you 16.5 by 12 tiles. Now multiply 16.5 by 12 and you have your total number of tiles.

4 0

2 years ago

Simita has 25 coins, consisting of 10c and 5c, which total $2.25. how many of each does she have?

Ilya [14]

Answer:

10c = 20

5c = 5

Step-by-step explanation:

Let x be the number of 10c coins; let y be the number of 5c coins. The total is $2.25, so the amount of 10c and 5c coins will add to that. Simita has 25 coins, so x and y, the number of coins, will have to add to 25. Hence, solve the simultaneous equation.

10x + 5y = 225 (1) - times by 0

x + y = 25 (2) - times by 5

10x + 5y = 225 (1)

5x + 5y = 125 (2)

Then, take equation 2 away from equation 1.

5x = 100

x = 20

Substitute x back into the original equation.

x + y = 25

20 + y = 25

y = 5

7 0

2 years ago

The average cost of living for a family of four in twelve different cities was found to be $65,351 with a standard deviation of

Andrej [43]

Answer:

$65,351+/-$3,661.73

= ( $61,689.27, $69,012.73)

Therefore, the 90% confidence interval (a,b) = ( $61,689.27, $69,012.73)

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x+/-zr/√n

Given that;

Mean x = $65,351

Standard deviation r = $7,711

Number of samples n = 12

Confidence interval = 90%

z(at 90% confidence) = 1.645

Substituting the values we have;

$65,351+/-1.645($7,711/√12)

$65,351+/-1.645($2,225.973962860)

$65,351+/-$3661.727168905

$65,351+/-$3,661.73

= ( $61,689.27, $69,012.73)

Therefore, the 90% confidence interval (a,b) = ( $61,689.27, $69,012.73)

6 0

3 years ago