Answer:
Step-by-step explanation:
a) H0:
Ha:
(Two tailed test at 5% significance level)
b) n=30
Mean difference =
Std error of mean =
b) Test statistic t = mean diff/std error = -1.552
df = 30-1 =29
p value=0.0657
c) Since p > 0.05 our signi. level, we accept null hypothesis.
There is no significant difference between the means.
d) Using critical value we find that test statistic is > critical value left
So accept H0
Answer:
tons of high steel and
tons of low steel
Step-by-step explanation:
Let x be the number of tons of high grade steel and y be the number of tons ow low grade steel needed.
In x tons of high grade steel there are
tons of iron
tons of magnese
In y tons of low grade steel there are
tons of iron
tons of magnese
NASA orders 500 tons of steel, so
and specifies that it must be in the proportion 80% iron and 20% magnese, so
From the first equation,
Substitute it into the second equation: