Answer:
41/24
Step-by-step explanation:
<h2><u>
Answer with explanation</u>
:</h2>
Let 
be the average life of light bulbs.
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.
Formula for Test statistic : 
where, n= sample size
= sample mean
= Population mean
=population standard deviation
For 
, we have
Using z-value table , Critical one-tailed test value for 0.06 significance level :
Decision : Since critical z value (1.5548) < test statistic (1.6180), so we reject the null hypothesis .
[We reject the null hypothesis when critical value is less than the test statistic value .]
Conclusion : We have enough evidence at 0.06 significance level to support the claim that the new filament yields a longer bulb life
Answer:
0.595.
Step-by-step explanation:
.
Answer:
$75
Step-by-step explanation:
If they have a total of w dollars to buy 5 tickets, and each ticket costs 15 dollars, $15 x 5 tickets = $75.
Let there be 2x science and 5x art books
<span>science books sold = 2x × 0.2 = 0.4x </span>
<span>science books unsold = 2x – 0.4x = 1.6x </span>
<span>art books sold = 5x × 0.2 = x </span>
<span>art books unsold = 5x – x = 4x </span>
<span>total books unsold = 1.6x + 4x = 5.6x </span>
<span>5.6x = 2240 </span>
<span>x = 400 </span>
<span>2x science = 800 </span>
<span>and 5x art books = 2000 </span>
