Answer: 0.6812
Step-by-step explanation:
Let p be the population proportion of trees are infested by a bark beetle.
As per given: p= 12%= 0.12
Sample size : n= 1000
Number of trees affected in sample = 1000
Sample proportion of trees are infested by a bark beetle. =
Now, the z-test statistic :
So,
Hence, the value of the z-test statistic = 0.6812 .
mark must leave it for 5.5 months or 5 and half moths to gain 5600 in interest .
<u>Step-by-step explanation:</u>
Here we have , mark invests 8000 in an account that pays 12% interest and 2000 in one that pays 8%. if he leaves the money in the accounts for the same length of time, We need to find how long must he leave it to gain 5600 in interest . Let's find out:
Let mark invests 8000 in an account that pays 12% interest and 2000 in one that pays 8% for time x months , So total interest gain is 5600 i.e.
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Therefore , mark must leave it for 5.5 months or 5 and half moths to gain 5600 in interest .