Answer:
Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Step-by-step explanation:
We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.
If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.
Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.
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<u>SO, Margin of error formula is given by;</u>
Margin of error =
where, = significance level = 10%
= standard deviation = 2.0
n = number of families
Now, in the z table the critical value of x at 5% ( ) level of significance is 1.645.
SO, Margin of error =
0.5 =
n =
= 43.3 ≈ 43
Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Answer:
189 cm^3
Step-by-step explanation:
7 times 9 times 3=189
Answer:
<u>8</u>
Step-by-step explanation:
The given monomial is :
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The degree of the monomial is the highest power to which a variable is raised to in the monomial. The greatest power in this case belongs to b⁸, which has a power of 8.
Hence, the degree of the monomial is <u>8</u>
Answer:
1070cm2
Step-by-step explanation:
the cereal box represents a cuboid and it is closed hence a closed cuboid.
SA- Surface area
L- Length = 15
W- Width =4
H- Height =25
In a closed cuboid, there are going to be 6 faces( 3 pairs).
To find SA, we have to take the area of all faces and sum them up.
You can do this by carrying out the area of all faces and summing them up or you can use the formula:
SA of a closed cuboid=2(L x W) + 2(W x H) + 2(L x H)
= 2(15 x 4) + 2(4 x 25) + 2(15 x 25)
= 2(60) + 2(100) + 2(375)
=120 + 200 + 750
=<u>1070cm2</u>