Answer:
Six numbers have perfect square factors
Step-by-step explanation:
The numbers with perfect square factors are those numbers that have perfect squares as one of the numbers that can divide them.
They include:
4 = 2 * 2
16 = 4 * 4
36 = 6 * 6
49 = 7 * 7
64 = 8 * 8
81 = 9* 9
These numbers above have perfect square factors because they are formed from integers that multiply themselves.
Answer:

And we can use the normal standard distribution table or excel and with the complement ruler we got:

Step-by-step explanation:
We know the following info given:
represent the true mean
represent the population deviation
represent the sample size selected
Since the sample size is large enough (n>30) we can use the central limit theorem and the sample mean would have the following distribution:

And for this case we want to find this probability:

And we can use the z score formula given by:

And replacing we got:

And we can use the normal standard distribution table or excel and with the complement ruler we got:

Answer:
Rate of the current: 19 kilometers per hour
Rate of the boat in still water: 80 kilometers per hour
Answer:
35.71m/s²
Step-by-step explanation:
using the formula force(F)=mass(m)×acceleration(a)
a =

F=15.0N
m=0.42kg
a=?
a=15÷0.42
a=35.71m/s²