Answer: c. z = 1.35; Reject the null hypothesis
Step-by-step explanation:
Let 
be the average life expectancy of its batteries.
As per given , we have
Null hypothesis : 
Alternative hypothesis : 
Since 
is right-tailed and population standard deviation is also known, so we perform right-tailed z-test.
Test statistic : 
where, n= sample size
= sample mean
= Population mean
=population standard deviation
For 
, we have
Critical one-tailed test value for 0.10 significance level :
Decision : Since critical z value (1.28) < test statistic (1.35), so we reject the null hypothesis .
[When critical value is less than the test statistic value , we reject the null hypothesis .]
<u>Answer:</u>
- 40% of the total marbles are green.
<u>Step-by-step explanation:</u>
Percentage: Green marbles/Total marbles
- => 8/5 + 4 + 8 + 3
- => 8/20
<u>Percentage formula:</u> 
<u />
- => 8/20 x 100
- => 8 x 5
- => 40
Hence, 40% of the total marbles are green.
Hoped this helped.
To solve for x:
Move all the terms containing "x" to the left side of the equation. Do this by adding x to both sides.
2x+x=3x. The new equation is:
3x-1/2=3
Now, move all terms not containing "x" to the right side of the equation. Do this by adding 1/2 to both sides.
3x=3+1/2 The new equation is:
3x=3 1/2, or 3.5
The final step is to isolate x. To do so, divide each side by 3.
3x/3 = 3 1/2 /3 The new equation is:
x=1 1/6
Answer:
the numbers who's difference is 16 and the product is 720 is
36 &20
Explanation:
to finding numbers you have to express the equation in a quadratic equation then Factor it.
since the two numbers have a difference of 16 you can say that the first number is x and the second number is x -16 then their product is 720.
x(x-16)=720
x²-16x=720
x²-16x-720=0
(x-36)(x+20)
there are two possible value of x but since you are looking for the positive value of x, choose the positive value of x the first number is 20.
To find the second number
x-16=20
x=20+16
x=36
the second number is 36
<u>Now </u><u>to </u><u>check</u>
<u>3</u><u>6</u><u>-</u><u>2</u><u>0</u><u>=</u><u>1</u><u>6</u>
<u>2</u><u>0</u><u>*</u><u>3</u><u>6</u><u>=</u><u>7</u><u>2</u><u>0</u>
