Just out of curiosity, what is (-7)-(+6)?

Emma has 460 ballet stickers in her collection. Each month she adds 28 more stickers to her collection.

MArishka [77]

I believe you would multiply 28 by 7, then add that to 460

3 0

3 years ago

Negative 15 plus 45 divided by 3

Furkat [3]

Answer:

10

Step-by-step explanation:

(-15+45)/3=10

3 0

3 years ago

Extreme cold and hot temperatures are known to affect the operation of electronic components. Winter is approaching and you are

Musya8 [376]

Answer:

A 95% confidence interval for the true mean minimum temperature that will damage an iPod is between 2.55°F and 7.45°F

Test statistic(Z) = 2.31

P-value = 0.0104

Step-by-step explanation:

Step 1

Null hypothesis: The average damaging temperature of nine iPods is 5°F

Alternate hypothesis: The average damaging temperature of nine iPods differs from 5°F

Step 2

Mean=5°F, Sd=3, df=n-1=9-1=8

The t-value corresponding to 8 degrees of freedom and 95% confidence level (5% significance level) is 2.306

Confidence Interval(CI) = (mean + or - t×sd/√n)

CI = (5 + 2.306×3/√8) = 5 + 6.918/2.828= 5+2.45=7.45°F

CI = (5 - 2.306×3/√8) = 5-2.45 = 2.55°F

Z = (sample mean - population mean)/(sd÷√n) = (5-2.55)/(3÷√8) = 2.45/1.061 = 2.31

Step 3

Using the standard distribution table, the cumulative area to the left of Z = 2.31 is 0.9896

P-value = 1 - 0.9896 = 0.0104

Step 4

Conclusion: A 95% confidence interval for the true mean minimum temperature that will damage an iPod is between 2.55°F and 7.45°F

7 0

4 years ago

The car travels an average of 40km per litre of fuel, and the cost of fuel is £1.25 per litre. Calculate the cost of the fuel fo

Nuetrik [128]

$31075 \div 40 = 776.875 \\ 776.875 \times 1.25 = 971.09375$
The cost of fuel was £971.09

5 0

4 years ago

Plz help me with this math and also explain

jasenka [17]

Step-by-step explanation:

SI = $250
Rate (R) = 12 $\sf \dfrac{1}{2}$ %
Time (t) = 4 years

$\longrightarrow \tt { SI = \dfrac{PRT}{100} } \\$

$\longrightarrow \tt { 250 = \dfrac{P \times 12\cfrac{1}{2} \times 4}{100} } \\$

$\longrightarrow \tt { 250 = \dfrac{P \times \cfrac{25}{2} \times 4}{100} } \\$

$\longrightarrow \tt { 250 = \dfrac{P \times 25 \times 2}{100} } \\$

$\longrightarrow \tt { 250 = \dfrac{P \times 50}{100} } \\$

$\longrightarrow \tt { 250 \times 100 = P \times 50} \\$

$\longrightarrow \tt { 25000 = P \times 50} \\$

$\longrightarrow \tt { \dfrac{25000}{50} = P } \\$

$\longrightarrow \underline{\boxed{ \green{ \tt { \$ \; 500 = P }}}} \\$

Therefore principal is $500.

2/7 of the balls are red.
3/5 of the balls are blue.
Rest are yellow.
Number of yellow balls = 36

Let the total number of balls be x.

→ Red balls + Blue balls + Yellow balls = Total number of balls

$\longrightarrow \tt{ \dfrac{2}{7}x + \dfrac{3}{5}x + 36 = x} \\$

$\longrightarrow \tt{ \dfrac{10x + 21x + 1260}{35} = x} \\$

$\longrightarrow \tt{ \dfrac{31x + 1260}{35} = x} \\$

$\longrightarrow \tt{ 31x + 1260= 35x} \\$

$\longrightarrow \tt{ 1260= 35x-31x} \\$

$\longrightarrow \tt{ 1260= 4x} \\$

$\longrightarrow \tt{ \dfrac{1260 }{4}= x} \\$

$\longrightarrow \underline{\boxed{ \tt { 315 = x }}} \\$

Total number of balls is 315.

A/Q,

3/5 of the balls are blue.

$\longrightarrow \tt{ Balls_{(Blue)} =\dfrac{3 }{5}x} \\$

$\longrightarrow \tt{ Balls_{(Blue)} =\dfrac{3 }{5}(315)} \\$

$\longrightarrow \tt{ Balls_{(Blue)} = 3(63)} \\$

$\longrightarrow \underline{\boxed{ \green {\tt { Balls_{(Blue)} = 189 }}}} \\$

8 0

3 years ago