Answer:
B. z Subscript alpha divided by 2 zα/2 = 1.96.
Step-by-step explanation:
We are given that we want to construct a confidence interval. For this, the summary statistics for randomly selected weights of newborn girls:
n = 236,
= 30.3 hg, s = 7.2 hg. The confidence level is 95%.
As we can clearly see here that the population standard deviation is unknown and the sample size is also very large.
It has been stated that when the population standard deviation is unknown, we should use t-distribution but since the sample size is very large so we can use z distribution also as it is stated that at very large samples; the t-distribution corresponds to the z-distribution.
Here,
= level of significance = 1 - 0.95 = 0.05 or 5%
= 0.025 or 2.5%
So, the value of
in the z table is given as 1.96 with a 2.5% level of significance.
$5 each car
3 hours = 12 cars
÷3 ÷3
1 hours = 4 cars
×8 ×8
8 hours = 32 cars
32 cars × $5 per car =
$160
They earned $160 in 8 hours, from washing 32 cars.
Answer:
111.2
Step-by-step explanation:
The square root and the ^2 cancel each other out so the number stays the same or 111.2
It could be PEMDAS.
That means solve by this order:
1). Parenthesis
2). Exponents
3). Multiplication
4). Division
5). Addition
6). Subtraction
To remember the order they say it like
this " Please Excuse My Dear Aunt Sally "
73+42 is correct because it’s addition