we know 140 is 5% of some number x. to find x, we use this formula: 140/x = 5/100
cross multiply: 14000 = 5x
divide each side by 5: 2800
they had $2800 in their account.
Let x = 78.3
y = 87.2
σₓ = 5.6 and σ₍y₎ = 6.3
number of pieces n = 50
z = z-score value =1.96 in this case
<span> A 100(1-α)%
confidence interval for the difference in large sample means is:
(x – y) ± z x </span>√( σₓ² / n+ σ₍y₎²<span>/n)
by putting the values,
=(78.3-87.2) </span>± 1.96 x √(5.6² /50 + 6.3² /50)<span>
</span><span>= -8.9 ± 2.34
</span><span>= [-11.24, -6.56]</span>
-21x+31 this is the answer you were looking for
Answer:
0.02510460251
Step-by-step explanation: